The Lindy Hop

The Wikipedia article on the history of Lindy Hop (which is not materially different from the article on Lindy Hop itself) says that the dance was "replaced by Rock and Roll dancing". Not entirely true. Compare this from the 1941 movie Hellzapoppin (featuring Whitey's Lindy Hoppers) with this by Bill Haley, from no earlier than 1956, and particularly compare these moves with these.  The only difference is the colour of the dancers.

More hoppin' from Whitey's hoppers here, some other dancing from the movie Swing Fever here, and see also a reconstruction, wonderfully done, from the film Malcolm X.  Note the same type of move here.  The tune 'Flying Home' was by Lionel Hampton, with a storming solo on saxophone by Illinois Jacquet.

Sadly, arguments over copyright mean that there is no sound for 'Lady be good' by Artie Shaw, where the dancing starts here, but there is a sound version without the pictures.  Don't miss Buddy Rich at 2m10s.

Mencken on crowdsourcing

I am half way through Francis Wheen’s excellent How Mumbo-Jumbo Conquered the World: A Short History of Modern Delusions.  Excellent, that is, apart from his apparent endorsement of Keynesian economics, which is no less mumbo-jumbo than any other piece of economics, but that's another story.  The section on creation science and evolution teaching summarises the issues clearly, and I was particularly taken with this quotation from Mencken:

The inferior man's reasons for hating knowledge are not hard to discern. He hates it because it is complex -- because it puts an unbearable burden upon his meager capacity for taking in ideas. Thus his search is always for short cuts. All superstitions are such short cuts. Their aim is to make the unintelligible simple, and even obvious. So on what seem to be higher levels. No man who has not had a long and arduous education can understand even the most elementary concepts of modern pathology. But even a hind at the plow can grasp the theory of chiropractic in two lessons. Hence the vast popularity of chiropractic among the submerged -- and of osteopathy, Christian Science and other such quackeries with it. They are idiotic, but they are simple -- and every man prefers what he can understand to what puzzles and dismays him.

The popularity of Fundamentalism among the inferior orders of men is explicable in exactly the same way. The cosmogonies that educated men toy with are all inordinately complex. To comprehend their veriest outlines requires an immense stock of knowledge, and a habit of thought. It would be as vain to try to teach to peasants or to the city proletariat as it would be to try to teach them to streptococci. But the cosmogony of Genesis is so simple that even a yokel can grasp it. It is set forth in a few phrases. It offers, to an ignorant man, the irresistible reasonableness of the nonsensical. So he accepts it with loud hosannas, and has one more excuse for hating his betters. [The Baltimore Evening Sun, June 29, 1925]

Very true, but I wonder what Mencken would have made of Wikipedia?

Philosophy in Wikipedia

There is an entertaining plug for philosophy in the Wikipedia signpost today. Sadly, it entirely conceals the ‘problems of philosophy’ in Wikipedia which I discussed last year in this post. As I noted then, there are serious problems with the ‘most important philosophy articles’ in Wikipedia.  Nine of these articles are of ‘C’ class. The article on Metaphysics is a mess, containing gems like “Nihilism represents and [sic] extremely negative view of being”. The article ‘History of Philosophy’, which is not even ‘C’ class, is just plain weird (“an historical perspective … emphasizes the existence of a long period of transition between the teologically [sic] driven centuries (running up the XIII or XIV Centuries) and the rationalists-empiricists debates”; “early and late Renaissance philosophers were a more heterogeneous population, including rhetors, magicians and astrologues, early empirical scientist, poets, philologists”).

The Signpost article mentions none of this. It begins by advertising the 44 featured articles in philosophy. Featured articles are those deemed good enough to be mentioned on Wikipedia’s main page. These 44 articles may be good, but most of them are nothing to do with philosophy, including Archimedes (not a philosopher), Emma Goldman (activist), History of evolutionary thought (science), Rabindranath Tagore (poet and mystic), The_Illuminatus! Trilogy (science fiction), Learned Hand (judge), Transhumanism (movement), and then continues with a sort of interview.

The two 'philosophy editors' interviewed are not actually philosophers in the proper sense.  One of them is a mathematician, the other a student of the Frankfurt School of critical theory (i.e. a sociologist).  

What is it about Wikipedia that makes dealing with philosophy so difficult?

Vallicella against singular concepts

Vallicella has a good post here about why he rejects individual concepts (aka singular concepts, haecceity concepts, singular meanings etc.).

His argument is that an individual concept, if there is such a thing, is either pure, or not. A pure concept C “involves no specific individual and can be grasped without reference to any specific individual”. If there such a concept C, or not. If there is, it is either pure or not. But every pure concept, no matter how specific, is possibly such as to have two or more instances. So C is not pure. But then it must involve an individual - the very individual of which it is the individual concept, and no individual can be grasped as such, and so C is not pure either. Thus there can be no such C.

I reply: the definition of “pure concept” is ambiguous, for the verb ‘involves’ is ambiguous between being logically transitive and logically intransitive. I discussed this idea back in March. A logically intransitive verb is one which has a grammatical accusative but no ‘logical’ accusative, i.e. such that ‘aRb’ can be true, without ‘Ex x=b’ being true. ‘Refers to’ is such a verb. Thus

(1) ‘Frodo’ refers to Frodo.

is true. And so is

(2) ‘Frodo’ refers to someone.

But

(3) Someone is such that ‘Frodo’ refers to them.

is not. If the verbs ‘involves’ and ‘grasps’ of Vallicella’s definition are logically intransitive, then the minor premiss of his argument – that we cannot grasp an individual – is questionable. For then you can grasp the concept of Frodo without any real relation to any existing individual.

To clarify, I hold that you can only grasp the concept of Frodo if you have read ‘Lord of the Rings’ (or some other book or text or body of information that references Frodo). It is analogous to ‘the former’ and ‘the latter’. These are descriptions which appear to be first-level, and to qualify the individuals referred to, but really, as it were, qualify the text itself (or the information received).

Borgesque thought-experiment: a Chinese author, who has never read Lord of the Rings, writes a very similar or identical work. I say that when people read this work and talk about the characters – say the one corresponding to Frodo – then they are not talking about Frodo. The right kind of causal connection to the work is not available. By contrast, if I read a sequel to LOTR in which Frodo appears as a character, and if I make it explicit the reference to Tolkien’s text, then I am referring to Frodo, and people who talk about my character are referring to him also. Thus, by the right kind of causal connection to a particular text (or mass-produced copies of it) we acquire individual concepts – in this case, individual concepts corresponding to things that do not exist.

The case of real history (e.g. Julius Caesar) is no different. There is no semantic connection between my individual concept of Caesar, and Caesar himself. But there is a connection between this concept and the historical texts I learned at school, or from books I read. It is this specific connection to items of information, texts etc. that guarantees the acquisition of individual concepts by different people, and their successful use to make individuating reference. What guarantees that we are thinking about Julius Caesar is the right kind of relation to a certain set of texts – not a relation to any existing person, which is irrelevant. What guarantees that we are all thinking about Frodo is exactly the same kind of relation. The existence of the individual referred to, and even their causal relation to the text, is irrelevant.

Singulars as universals

In the context of the present discussion there is yet another argument against the scholastic treatment of singular terms as (implicitly) quantified universal terms.  Colwyn Williamson, in the article 'traditional logic', in The Oxford Companion to Philosophy writes:

In the traditional textbooks, singulars are treated as universals, on the feeble pretext that in 'Socrates is bald' the name 'Socrates' refers to everything it can. This notion was generally expressed in technical terminology: the name was said to be 'distributed' or to 'refer to its whole extension'. These obscurities presumably reflect a disinclination to say something that is obviously absurd (that one is talking about the whole of Socrates), something that is obviously false (that only one person can be called Socrates), or something that is obviously vacuous (that the name is here meant to name everyone it is here meant to name). 

Do we need identity?

There is the usual vigorous debate going on at Maverick's place, this time about whether proper names can be predicated.  I have been expecting at any minute the objection that we must distinguish between the 'is' of predication and the 'is' of identity, but no sign of it yet.

Let me explain.  In natural language we say things like 'this person is Socrates' or 'that star is the planet Venus'.  We are putting a proper name ('Socrates', 'Venus') in a part of the sentence logic normally reserves for the 'predicate'.  But in modern predicate calculus (MPC) proper names cannot occur as predicates.  We owe it to Frege (as Geach says) that modern logicians accept an absolute category difference between name and predicate, so that in MPC the two types are syntactically different: small letters for proper names, and propositional functions for the predicates.  Thus 'F(a)' represents 'Socrates is running', where 'a' represents Socrates, and F( ) the function '-- is running'.

But what about 'this person is Socrates'?  Ah, that is because we must distinguish the 'is' of identity from the 'is' of predication.  We are not predicating 'Socrates' of this person, but rather the propositional function '-- is identical with Socrates'.  Thus, as Frege says (in "On Concept and Object"), a proper name like 'Venus' can never be a predicate, although it can form part of a predicate. 

That is all pretty standard stuff, but is it the knock-down argument against scholastic logic that it appears to be?  I just looked again at Fred Sommers' excellent book* defending Traditional Formal Logic.  In the chapter 'Do we need identity' he asks why no logicians before Frege had appealed to the distinction between the two kinds of 'is', and argues that the distinction depends on making the category distinction between concept-word (predicate) and object-word (proper name) rather than the other way round.  Thus, it is only after we take on the odd representation of ordinary language sentences as propositional function and argument, that we are forced to make the distinction between the two forms of 'is'.  It is not that we first recognise the distinction as a fundamental principle that forces the odd syntax upon us. 

Sommers argues as follows (p. 121 - I have modified his argument slightly in order to strengthen it).  When we represent ordinary proper names (say 'Venus' and 'the morning star') as logical constants, we use lower cases letters, say 'a' and 'b'.  But then the representation of 'Venus is the morning star' as 'b(a)' is ill-formed.  The lower case letter 'b' cannot appear in predicate place.  It is therefore obvious, says Sommers ironically, that it really has the form 'F(a,b), where 'F' is the grammatical predicate which represents '-- is identical with --'.  "Clearly, it is only after one has adopted the syntax that prohibits the predication of proper names that one is forced to read 'a is b' dyadically and to see in it a sign of identity".


* Fred Sommers, The Logic of Natural Language, Clarendon 1982.

165 objections to global warming

I just found this handy guide to sceptical arguments against ‘global warming’. There are 165 arguments in all, organised in order of supposed popularity or frequency.

I ignored this ordering and – because this is merely a logic blog – reclassified them by type of argument. In logical order, they are as follows. ‘Wrong effect’ is the objection that there is no warming, or that the observational data do not support the thesis that any such warming is statistically significant. ‘Wrong methodology’ is the negative claim that the evidence does not support the presumed causal relationship between greenhouse emissions and warming. ‘Wrong cause’ is the positive claim that, although warming is conceded, the cause is different from the standard one (i.e. greenhouse effect caused by industrialisation). ‘Lack of authority’ is the objection that there is no real scientific consensus about warming, or the cause-effect relationship. ‘Wrong consequence’ concedes the warming, and the causal relationship, but denies any real consequences. Finally, ‘We can’t prevent it’ concedes absolutely everything – disastrous consequences and all – but says there is no point in doing anything, because nothing would be effective anyway.

I will discuss these arguments in later posts, but my point for today is that none of these objections hit my sceptical worry about the global warming hypothesis (which I have defined as the hypothesis that greenhouse emissions will have potentially disastrous consequences for the world). The claim that ‘we can’t prevent it’ is not part of the hypothesis. The objection about scientific consensus is a form of ad hominem, which is a logical fallacy (although looking for agreement among experts is a useful heuristic to guide non-experts, and is the basis of most peer-review processes, and the underlying reason for examinations and qualifications and suchlike). Positive claims of ‘wrong cause’ are a form of straw man, and are also not properly sceptical (a sceptic avoids making any positive claim, preferring to question or express reasonable doubt). When replying to an argument, we must demonstrate what is wrong with the argument itself, or what is wrong with the premisses. Merely contradicting the conclusion, even for good reason, is not enough. That leaves ‘wrong effect’, ‘wrong methodology’ and ‘wrong consequence’, which I will discuss tomorrow.

Meanwhile, as a preliminary, you may want to revisit our old friends propter quid and quia, in particular, and more generally the posts about Aristotle’s Posterior Analytics.

Wrong effect (56)
142 "It warmed just as fast in 1860-1880 and 1910-1940" The warming trend over 1970 to 2001 is greater than warming from both 1860 to 1880 and 1910 to 1940.
21 "1934 - hottest year on record" 1934 was one of the hottest years in the US, not globally.
17 "Glaciers are growing" Most glaciers are retreating, posing a serious problem for millions who rely on glaciers for water.
9 "It hasn't warmed since 1998" For global records, 2010 is the hottest year on record, tied with 2005.
10 "Antarctica is gaining ice" Satellites measure Antarctica losing land ice at an accelerating rate.
7 "Temp record is unreliable" The warming trend is the same in rural and urban areas, measured by thermometers and satellites.
1 "Climate's changed before" Climate reacts to whatever forces it to change at the time; humans are now the dominant forcing.
4 "It's cooling" The last decade 2000-2009 was the hottest on record.
15 "Hockey stick is broken" Recent studies agree that recent global temperatures are unprecedented in the last 1000 years.
23 "It's freaking cold!" A local cold day has nothing to do with the long-term trend of increasing global temperatures.
25 "Sea level rise is exaggerated" A variety of different measurements find steadily rising sea levels over the past century.
26 "It's Urban Heat Island effect" Urban and rural regions show the same warming trend.
28 "Arctic icemelt is a natural cycle" Thick arctic sea ice is undergoing a rapid retreat.
30 "Medieval Warm Period was warmer" Globally averaged temperature now is higher than global temperature in medieval times.
31 "It's a 1500 year cycle" Ancient natural cycles are irrelevant for attributing recent global warming to humans.
85 "Record snowfall disproves global warming" Warming leads to increased evaporation and precipitation, which falls as increased snow in winter.
144 "Antarctica is too cold to lose ice" Glaciers are sliding faster into the ocean because ice shelves are thinning due to warming oceans.
164 "Ljungqvist broke the hockey stick" Ljungqvist's temperature reconstruction is very similar to other reconstructions by Moberg and Mann.
152 "DMI show cooling Arctic" While summer maximums have showed little trend, the annual average Arctic temperature has risen sharply in recent decades.
151 "Greenland has only lost a tiny fraction of its ice mass" Greenland's ice loss is accelerating & will add metres of sea level rise in upcoming centuries.
139 "Record high snow cover was set in winter 2008/2009" Winter snow cover in 2008/2009 was average while the long-term trend in spring, summer, and annual snow cover is rapid decline.
140 "Sea level is not rising" The claim sea level isn’t rising is based on blatantly doctored graphs contradicted by observations.
135 "The sun is getting hotter" The sun has just had the deepest solar minimum in 100 years.
125 "Ice Sheet losses are overestimated" A number of independent measurements find extensive ice loss from Antarctica and Greenland.
120 "IPCC ‘disappeared’ the Medieval Warm Period" The IPCC simply updated their temperature history graphs to show the best data available at the time.
114 "Earth hasn't warmed as much as expected" This argument ignores the cooling effect of aerosols and the planet's thermal inertia.
115 "Sea level rise is decelerating" Global sea level data shows that sea level rise has been increasing since 1880 while future sea level rise predictions are based on physics, not statistics.
113 "Ice isn't melting" Arctic sea ice has shrunk by an area equal to Western Australia, and summer or multi-year sea ice might be all gone within a decade.
110 "Arctic sea ice loss is matched by Antarctic sea ice gain" Arctic sea ice loss is three times greater than Antarctic sea ice gain.
99 "Dropped stations introduce warming bias" If the dropped stations had been kept, the temperature would actually be slightly higher.
96 "Tree-rings diverge from temperature after 1960" This is a detail that is complex, local, and irrelevant to the observed global warming trend.
91 "Southern sea ice is increasing" Antarctic sea ice has grown in recent decades despite the Southern Ocean warming at the same time.
92 "IPCC overestimate temperature rise" Monckton used the IPCC equation in an inappropriate manner.
93 "It's microsite influences" Microsite influences on temperature changes are minimal; good and bad sites show the same trend.
90 "Arctic was warmer in 1940" The actual data show high northern latitudes are warmer today than in 1940.
81 "Global warming stopped in 1998, 1995, 2002, 2007, 2010, ????" Global temperature is still rising and 2010 was the hottest recorded.
77 "Springs aren't advancing" Hundreds of flowers across the UK are flowering earlier now than any time in 250 years.
63 "It's the ocean" The oceans are warming and moreover are becoming more acidic, threatening the food chain.
61 "IPCC were wrong about Himalayan glaciers" Glaciers are in rapid retreat worldwide, despite 1 error in 1 paragraph in a 1000 page IPCC report.
49 "It warmed before 1940 when CO2 was low" Early 20th century warming is due to several causes, including rising CO2.
50 "Satellites show no warming in the troposphere" The most recent satellite data show that the earth as a whole is warming.
43 "Arctic sea ice has recovered" Thick arctic sea ice is in rapid retreat.
32 "Oceans are cooling" The most recent ocean measurements show consistent warming.
128 "Satellite error inflated Great Lakes temperatures" Temperature errors in the Great Lakes region are not used in any global temperature records.
41 "There's no empirical evidence" There are multiple lines of direct observations that humans are causing global warming.
36 "Greenland was green" Other parts of the earth got colder when Greenland got warmer.
37 "Greenland is gaining ice" Greenland on the whole is losing ice, as confirmed by satellite measurement.
38 "Polar bear numbers are increasing" Polar bears are in danger of extinction as well as many other species.
39 "It's not happening" There are many lines of evidence indicating global warming is unequivocal.
46 "It cooled mid-century" Mid-century cooling involved aerosols and is irrelevant for recent global warming.
44 "We're coming out of the Little Ice Age" Scientists have determined that the factors which caused the Little Ice Age cooling are not currently causing global warming
54 "Mt. Kilimanjaro's ice loss is due to land use" Most glaciers are in rapid retreat worldwide, notwithstanding a few complicated cases.
55 "There's no tropospheric hot spot" We see a clear "short-term hot spot" - there's various evidence for a "long-term hot spot".
56 "2009-2010 winter saw record cold spells" A cold day in Chicago in winter has nothing to do with the trend of global warming.
141 "We're heading into cooling" There is no scientific basis for claims that the planet will begin to cool in the near future.
13 "We're heading into an ice age" Worry about global warming impacts in the next 100 years, not an ice age in over 10,000 years.

Wrong methodology (5)
58 "Scientists can't even predict weather" Weather and climate are different; climate predictions do not need weather detail.
123 "Climate is chaotic and cannot be predicted" Weather is chaotic but climate is driven by Earth's energy imbalance, which is more predictable.
131 "Soares finds lack of correlation between CO2 and temperature" Soares looks at short-term trends which are swamped by natural variations while ignoring the long-term correlation.
82 "The science isn't settled" That human CO2 is causing global warming is known with high certainty & confirmed by observations.
6 "Models are unreliable" Models successfully reproduce temperatures since 1900 globally, by land, in the air and the ocean.

Wrong cause (60)
65 "It's not us" Multiple sets of independent observations find a human fingerprint on climate change.
68 "CO2 effect is saturated" Direct measurements find that rising CO2 is trapping more heat.
70 "Clouds provide negative feedback" Evidence is building that net cloud feedback is likely positive and unlikely to be strongly negative.
71 "Volcanoes emit more CO2 than humans" Humans emit 100 times more CO2 than volcanoes.
124 "Melting ice isn't warming the Arctic" Melting ice leads to more sunlight being absorbed by water, thus heating the Arctic.
157 "It's internal variability" Internal variability can only account for small amounts of warming and cooling over periods of decades, and scientific studies have consistently shown that it cannot account for the global warming over the past century.
2 "It's the sun" In the last 35 years of global warming, sun and climate have been going in opposite directions
20 "It's cosmic rays" Cosmic rays show no trend over the last 30 years & have had little impact on recent global warming.
24 "Extreme weather isn't caused by global warming" Extreme weather events are being made more frequent and worse by global warming.
94 "CO2 is not the only driver of climate" Theory, models and direct measurement confirm CO2 is currently the main driver of climate change.
95 "It's albedo" Albedo change in the Arctic, due to receding ice, is increasing global warming.
79 "It's land use" Land use plays a minor role in climate change, although carbon sequestration may help to mitigate.
89 "Solar Cycle Length proves its the sun" The sun has not warmed since 1970 and so cannot be driving global warming.
107 "It's a climate regime shift" There is no evidence that climate has chaotic “regimes” on a long-term basis.
112 "Solar cycles cause global warming" Over recent decades, the sun has been slightly cooling & is irrelevant to recent global warming.
137 "It's waste heat" Greenhouse warming is adding 100 times more heat to the climate than waste heat.
159 "It's satellite microwave transmissions" Satellite transmissions are extremely small and irrelevant.
161 "CO2 only causes 35% of global warming" CO2 and corresponding water vapor feedback are the biggest cause of global warming.
162 "We didn't have global warming during the Industrial Revolution" CO2 emissions were much smaller 100 years ago.
156 "CO2 limits won't cool the planet" CO2 limits won't cool the planet, but they can make the difference between continued accelerating global warming to catastrophic levels vs. slowing and eventually stopping the warming at hopefully safe levels
136 "Mauna Loa is a volcano" The global trend is calculated from hundreds of CO2 measuring stations and confirmed by satellites.
149 "Warming causes CO2 rise" Recent warming is due to rising CO2.
33 "Human CO2 is a tiny % of CO2 emissions" The natural cycle adds and removes CO2 to keep a balance; humans add extra CO2 without removing any.
34 "Water vapor is the most powerful greenhouse gas" Rising CO2 increases atmospheric water vapor, which makes global warming much worse.
51 "CO2 was higher in the past" When CO2 was higher in the past, the sun was cooler.
126 "A drop in volcanic activity caused warming" Volcanoes have had no warming effect in recent global warming - if anything, a cooling effect.
129 "Breathing contributes to CO2 buildup" By breathing out, we are simply returning to the air the same CO2 that was there to begin with.
47 "There's no correlation between CO2 and temperature" There is long-term correlation between CO2 and global temperature; other effects are short-term.
84 "CO2 is not increasing" CO2 is increasing rapidly, and is reaching levels not seen on the earth for millions of years.
86 "CO2 is coming from the ocean" The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.
45 "CO2 is not a pollutant" Through its impacts on the climate, CO2 presents a danger to public health and welfare, and thus qualifies as an air pollutant
145 "Water levels correlate with sunspots" This detail is irrelevant to the observation of global warming caused by humans.
146 "CO2 was higher in the late Ordovician" The sun was much cooler during the Ordovician.
147 "It's CFCs" CFCs contribute at a small level.
57 "It's Pacific Decadal Oscillation" The PDO shows no trend, and therefore the PDO is not responsible for the trend of global warming.
59 "It's a natural cycle" No known natural forcing fits the fingerprints of observed warming except anthropogenic greenhouse gases.
73 "It's methane" Methane plays a minor role in global warming but could get much worse if permafrost starts to melt.
100 "Humans are too insignificant to affect global climate" Humans are small but powerful, and human CO2 emissions are causing global warming.
29 "Increasing CO2 has little to no effect" The strong CO2 effect has been observed by many different measurements.
143 "Venus doesn't have a runaway greenhouse effect" Venus very likely underwent a runaway or ‘moist’ greenhouse phase earlier in its history, and today is kept hot by a dense CO2 atmosphere.
133 "Water vapor in the stratosphere stopped global warming" This possibility just means that future global warming could be even worse.
134 "CO2 emissions do not correlate with CO2 concentration" That humans are causing the rise in atmospheric CO2 is confirmed by multiple isotopic analyses.
75 "Humidity is falling" Multiple lines of independent evidence indicate humidity is rising and provides positive feedback.
52 "It's aerosols" Aerosols have been masking global warming, which would be worse otherwise.
97 "It's soot" Soot stays in the atmosphere for days to weeks; carbon dioxide causes warming for centuries.
103 "It's global brightening" This is a complex aerosol effect with unclear temperature significance.
119 "It's ozone" Ozone has only a small effect.
53 "It's El Niño" El Nino has no trend and so is not responsible for the trend of global warming.
40 "Other planets are warming" Mars and Jupiter are not warming, and anyway the sun has recently been cooling slightly.
88 "Pluto is warming" And the sun has been recently cooling.
27 "Mars is warming" Mars is not warming globally.
76 "Neptune is warming" And the sun is cooling.
78 "Jupiter is warming" Jupiter is not warming, and anyway the sun is cooling.
80 "CO2 measurements are suspect" CO2 levels are measured by hundreds of stations across the globe, all reporting the same trend.
74 "CO2 has a short residence time" Excess CO2 from human emissions has a long residence time of over 100 years
12 "CO2 lags temperature" CO2 didn't initiate warming from past ice ages but it did amplify the warming.
154 "Positive feedback means runaway warming" Positive feedback won't lead to runaway warming; diminishing returns on feedback cycles limit the amplification.
18 "Climate sensitivity is low" Net positive feedback is confirmed by many different lines of evidence.
60 "2nd law of thermodynamics contradicts greenhouse theory" The 2nd law of thermodynamics is consistent with the greenhouse effect which is directly observed.
72 "Greenhouse effect has been falsified" The greenhouse effect is standard physics and confirmed by observations.

Lack of authority (24)
5 "There is no consensus" 97% of climate experts agree humans are causing global warming.
11 "Ice age predicted in the 70s" The vast majority of climate papers in the 1970s predicted warming.
19 "Al Gore got it wrong" Al Gore book is quite accurate, and far more accurate than contrarian books.
22 "Climategate CRU emails suggest conspiracy" A number of investigations have cleared scientists of any wrongdoing in the media-hyped email incident.
35 "IPCC is alarmist" The IPCC summarizes the recent research by leading scientific experts.
83 "500 scientists refute the consensus" Around 97% of climate experts agree that humans are causing global warming.
87 "Scientists tried to 'hide the decline' in global temperature" The 'decline' refers to a decline in northern tree-rings, not global temperature, and is openly discussed in papers and the IPCC reports.
108 "Peer review process was corrupted" An Independent Review concluded that CRU's actions were normal and didn't threaten the integrity of peer review.
109 "Less than half of published scientists endorse global warming" Around 97% of climate experts agree that humans are causing global warming.
101 "Lindzen and Choi find low climate sensitivity" Lindzen and Choi’s paper is viewed as unacceptably flawed by other climate scientists.
104 "Phil Jones says no global warming since 1995" Phil Jones was misquoted.
105 "Hansen's 1988 prediction was wrong" Jim Hansen had several possible scenarios; his mid-level scenario B was right.
117 "Over 31,000 scientists signed the OISM Petition Project" The 'OISM petition' was signed by only a few climatologists.
163 "Hansen predicted the West Side Highway would be underwater" Hansen was speculating on changes that might happen if CO2 doubled.
153 "Skeptics were kept out of the IPCC?" Official records, Editors and emails suggest CRU scientists acted in the spirit if not the letter of IPCC rules.
160 "Royal Society embraces skepticism" The Royal Society still strongly state that human activity is the dominant cause of global warming.
116 "Freedom of Information (FOI) requests were ignored" An independent inquiry found CRU is a small research unit with limited resources and their rigour and honesty are not in doubt.
121 "Naomi Oreskes' study on consensus was flawed" Benny Peiser, the Oreskes critic, retracted his criticism.
122 "Trenberth can't account for the lack of warming" Trenberth is talking about the details of energy flow, not whether global warming is happening.
130 "The IPCC consensus is phoney" 113 nations signed onto the 2007 IPCC report, which is simply a summary of the current body of climate science evidence
64 "IPCC were wrong about Amazon rainforests" The IPCC statement on Amazon rainforests was correct, and was incorrectly reported in some media.
132 "CRU tampered with temperature data" An independent inquiry went back to primary data sources and were able to replicate CRU's results.
106 "They changed the name from global warming to climate change" 'Global warming' and 'climate change' mean different things and have both been used for decades.
148 "Scientists retracted claim that sea levels are rising" The Siddall 2009 paper was retracted because its predicted sea level rise was too low.

Wrong consequences (12)
3 "It's not bad" Negative impacts of global warming on agriculture, health & environment far outweigh any positives.
8 "Animals and plants can adapt" Global warming will cause mass extinctions of species that cannot adapt on short time scales.
14 "Ocean acidification isn't serious" Past history shows that when CO2 rises quickly, there was mass extinctions of coral reefs.
16 "Hurricanes aren't linked to global warming" There is increasing evidence that hurricanes are getting stronger due to global warming.
155 "It's only a few degrees" A few degrees of global warming has a huge impact on ice sheets, sea levels and other aspects of climate.
138 "An exponential increase in CO2 will result in a linear increase in temperature" CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.
111 "It's not urgent" A large amount of warming is delayed, and if we don’t act now we could pass tipping points.
150 "Coral atolls grow as sea levels rise" Thousands of coral atolls have "drowned" when unable to grow fast enough to survive at sea level.
69 "Corals are resilient to bleaching" Globally about 1% of coral is dying out each year.
48 "CO2 is plant food" The effects of enhanced CO2 on terrestrial plants are variable and complex and dependent on numerous factors
66 "Greenland ice sheet won't collapse" When Greenland was 3 to 5 degrees C warmer than today, a large portion of the Ice Sheet melted.
67 "Sea level rise predictions are exaggerated" Sea level rise is now increasing faster than predicted due to unexpectedly rapid ice melting.

We can’t prevent it (8)
165 "Removing all CO2 would make little difference" Removing CO2 would cause most water in the air to rain out and cancel most of the greenhouse effect.
158 "Renewable energy investment kills jobs" Investment in renewable energy creates more jobs than investment in fossil fuel energy.
118 "It's too hard" Scientific studies have determined that current technology is sufficient to reduce greenhouse gas emissions enough to avoid dangerous climate change.
127 "Renewables can't provide baseload power" A combination of renewables supplemented with natural gas can provide baseload power.
42 "CO2 limits will harm the economy" The benefits of a price on carbon outweigh the costs several times over.
62 "CO2 limits will hurt the poor" Those who contribute the least greenhouse gases will be most impacted by climate change.
98 "CO2 limits will make little difference" If every nation agrees to limit CO2 emissions, we can achieve significant cuts on a global scale.
102 "Renewable energy is too expensive" When you account for all of the costs associated with burning coal and other fossil fuels, like air pollution and health effects, in reality they are significantly more expensive than most renewable energy sources.

Recognisably kitsch?

I recently finished Thomas Kulka’s interesting book on kitsch, where he takes a philosophical approach to the problem of defining kitsch. More about that later, perhaps. Until then, Vallicella has something about it here, with links.
Right now, I am wondering about Jack Vettriano. John Nicholson is auctioning some of his work next week – expect to pay between £60,000 and £100,000. Is it kitsch? One danger sign is that a significant number of hotels I have visited in the past five years have a Vettriano reproduction sitting somewhere. There is an interesting discussion here, with more danger signs. Practically every popular discussion of kitsch will involve one party asserting that “neither the Metropolitan nor MOMA have sunk so low as to be hanging X”, with the other party strenuously asserting stuff like “publicly funded art galleries [should not be] a pure platform for top-down “elite” education of the Masses” and “why are the elite curators presupposed to have better “prejudices” than the masses?” Another danger sign is “I know what I like”.

I don’t know about Vettriano. The main problem with kitsch is that it is not always obvious, during its period of popularity, that it is kitsch. It’s only, say, thirty or more years later that it becomes obviously and instantaneously recognisable for what it is.

Global warming random walks

Someone mentioned randomness in an earlier post, and raised the problem of how it can exist in a (fairly) deterministic universe. Reply: this should not be a problem any more than the ‘randomness’ of the roulette wheel. Once the ball has left the hand of the croupier at a determinate momentum and velocity and place, and once the wheel is spinning without interference with determinate angular momentum, it is determinate where the ball will land. The physics of roulette is discussed here. But as Aristotle noted (somewhere) such determinism is nevertheless perfectly consistent with the appearance of randomness. Without accurate measuring equipment, and with the aid only of sight and hearing, we cannot predict where the roulette ball will fall, and so the outcome of each roulette game is effectively random (i.e. the statistical properties of the outcomes are not inconsistent with randomness). In roughly the same sense (I imagine) we cannot predict weather accurately. There is something about this here.

This does not mean that global warming is random, of course. As I understand it (I am sure the commenters will correct me if I am wrong), climate physics predicts an equilibrium temperature corresponding to any concentration of greenhouse gases in the atmosphere. All other things being equal, the temperature will revert over time to this value. But there are many forces pushing the climate away from and towards this equilibrium. There are cyclical forces pushing away from the equilibrium and back, e.g. the seasons. Summers tend to be warmer, winters colder, as we all know. In addition to this, there are apparently random deviations from these seasonal values which can be quite extreme.

The chart above shows the deviation of December minimum temperatures (as measured in Oxford) from 1853 to 2010 from the average minimum December temperature for all years. The mean is zero, but there is considerable deviation from that mean. Notable outliers are the Decembers of 1890, which is discussed here; 1962, which I remember as a young lad, when the sea froze and there was widespread disruption; 1981, when I was trapped in Wales for a few days in heavy snowfall; and 2010, when we even had snow in London.

While we are on the subject of the book of Revelation (see previous post), here are some different versions of 'John the Revelator'. The one from the Blues Brothers film has a nice gospelly feel to it, but my favourite is the delta bluesy version by Blind Willie Johnson. I also like this energetic version by the White Stripes.

The Seven Seals is a phrase used in the Book of Revelation to refer to the symbolic seals that seal the "book" or "scroll" that John of Patmos saw in his vision.

Who is Antichrist?

In medieval logic 'Antichrist' was a proper name frequently used as an example of reference to an individual who does not exist now, but will exist, just as 'Caesar' was the stock example of reference to an individual who does not exist now, but used to exist. This may help to illuminate the curious discussion going on at Vallicella's place. For all the following statements are (almost uncontroversially) true, in my opinion.

(1) At least some of the biblical texts (including Daniel 7, 8 and 11, Revelation 13 and 17) claim to make identifying reference to a man or creature who would rise up against God and the 'Son of Man', and who would wage war on the saints. For example, Daniel (7:8) claims to have seen the person in a dream, a direct revelation of the future ("and behold eyes like the eyes of a man were in this horn, and a mouth speaking great things"). Thus, even if the prophets weren't making an identifying reference, they thought they were.

(2) When the medieval scholars used the term 'Antichrist', they were aiming to refer to the same individual that prophets thought they were referring to. Thus the name 'Antichrist' was used, and is used, with the aim of making an identifying reference.

(3) Various descriptions of Antichrist are given in the biblical texts, in order that we might recognise him. Hence the question arises, even now, if whether certain individuals who exist now should be identified as Antichrist. Eg. Ian Paisley denounced Pope John Paul II as the Antichrist in 1988, and many people in America think that Obama is Antichrist.

(4) But the significance of the name should not be confused with any description by means of which we are told to recognise Antichrist. If the name signified the description, the identity would have the status of a logical truth, and we could not reasonably question whether anyone satisfying that description was Antichrist.

In summary, the name 'Antichrist' is a singular term used to make an identifying reference, or with the aim of doing that. Thus it makes an identifying reference to an individual who probably does not exist yet, or aims to make such a reference (in the case that Antichrist never exists). It is not a description, for there are individuals satisfying the description of whom one could reasonably deny they are Antichrist. E.g. when I say that Obama is not Antichrist, I am not denying a logical truth.

Debt and equity

I continue to fret about what the world would look like if all finance were 'Islamic'.  What would equity look like?  The liabilities of a normal company are typically split between about 10% of 'equity' and 90% of 'debt'.  The debt is a deterministic liability that involves the repayment of principal at a determined maturity, and an agreed and fixed coupon payable at agreed intervals.  The equity is merely the difference between the current value of the assets and the debt.  This gives two advantages to the person who owns the equity.  (1) Any of the asset income stream that remains after the coupon has been paid belongs to the equity holder, as does any capital gain resulting from the increase in asset value.  And (2) if the asset value falls below the debt, the equity holder can walk away from the company, which will fall into the hands of the creditors, the owners of the debt (at least, assuming the company is limited liability).  The first advantage gives a strong incentive to the equity holder to reduce costs of the assets, and maximise the income. The second means that the losses of the equity holder are limited to the equity.  This gives a chance for those with limited capital to set up in business, without the risk of materially large losses.

Under an Islamic system, no deterministic liabilities (i.e. 'debt') are allowed. All investors in the company must share the risk of a fall in the value of the assets, and all must share the rewards.  In effect, it makes every investor an equity holder, and dilutes the possibility of extraordinary profits available under the debt-equity system. Could a modern capitalistic economy thrive under such a system? 

Future identifying reference

Vallicella is agonising here (see also here) about the problem of how (or whether) it is possible to identify individuals who do not exist, but will exist in the future. This requires that there must be a way to individuate all possible individuals that in no way depends upon their actual existence. But that in turn means that 'haecceities' must exist - supposed non-descriptive properties that have no other function than to belong to the very individual they belong to. Or as Vallicella puts it:

A haecceity is a property H of x such that: (i) H is essential to x; (ii) nothing distinct from x exemplifies H in the actual world; (iii) nothing distinct from x exemplifies H in any metaphysically possible world.

Vallicella takes it for granted there cannot be haecceities. They are 'creatures of darkness'. But assuming there aren't, the problem is that if God is omniscient (i.e. knows everything that is, has been and will be) then he must have known which individuals he was going to create when he created the world. (For example, he must have known he was going to create Socrates). This cannot be explained without presuming haecceities (per Vallicella). Since there are no such things, God is not omniscient.

I reply: if we can make an identifying reference for items that exist now ('this baby here'), and items that existed in the past ('Isaiah'), why can't we make identifying references in the future? Isn't the 'he' below such a future identifying reference? Does it require a haecceity existing when Isaiah made the prophesy? Why? Why can't the reference reach over the future centuries in order to identify the yet-to-be-born Jesus?

For to us a child is born,
to us a son is given,
and the government will be on his shoulders.
And he will be called
Wonderful Counselor, 
Mighty God,
Everlasting Father,
Prince of Peace. [Isaiah 9:6]

A matter of numbers

I have been having a fairly ‘vigorous’ discussion with Brandon Watson here, about fair pricing of financial contracts in general and, more specifically, the practice of making such contracts ‘Sharia compliant’, which, as far as I can see, consists in taking products which have a built-in and unavoidable interest rate cost, and disguising that cost by calling it something else, such as a fee or planning cost or whatever. Brandon has replied with the fairly astonishing claim that “you seem to have the odd idea that fairness in contract is a matter of numbers.”

Fairness is about being is transparent as possible the source of the product costs, and hence the amount of profit. That’s why companies have accountants, and is why, indeed, accountants are called ‘accountants’. Many of the recent problems in the financial area stem precisely from a lack of transparency. 

Most retail banking and investment products are simply cobbled together from products freely available in the wholesale markets, traded at market rates, or are internal products whose risk and price can easily be computed by a financial model of some kind. An annuity, for example. The simplest form of annuity is a product that pays you a fixed and agreed sum of money on a monthly basis from a certain age until you die, in return for a lump sum paid in advance by you. Annuities are the building block of all pensions, of which probably every person in any developed country has at least one. They are a basic, as well as very important financial product. The price of an annuity is also very simple to calculate. You begin with a set of long term government bond rates, which pay a fixed sum far into the future. Then you apply a set of mortality rates which work out the probability of you being alive in any of the years in which you hold the annuity. These allow the provider to work out the fair value ‘spread’ over the government bond yield which it can afford to pay, before the annuitant dies. A fair value annuity is thus one where the mortality-adjusted value of the excess spread exactly balances the profit the provider will receive by owning the bond after the annuitant dies. This fair value can be objectively calculated by using government bond rates – objectively verifiable – and statistical tables, also available from the government. Thus, in this case and most others - pace Brandon - fairness in contract is entirely a matter of numbers.

Of course, the product provider will rarely explain this to you, and will almost certainly hide the fact that standard products like annuities are available almost at cost, if you know where to look. There is little profit in providing such standard pension products. You are more likely to be sold a ‘wrapper’ or pension plan of some kind which combines a standard annuity with other wrinkles such as other forms of insurance, investment plans and early redemption options, all of which are also individually available at a fair cost, plus a whacking great hidden charge, of course. The salesman’s main job will be to emphasise the (geniune) attractiveness of the product, while minimising any hidden risks and hidden charges – one of which will be a handsome fee for ‘advising’ you.

Reform of the financial system involves changing the law to force providers to disclose hidden charges, and to be explicit about the true costs. ‘Sharia-compliant’ products seem like a retrograde step, in my view. They tend to make the raw costs of the product completely opaque to the customer, for the reason that making them explicit would make them immoral, from the customer’s standpoint. How would you construct a Sharia compliant annuity? Impossible, in my view, and the experts seem to agree. Attempts to provide a different product that is not a genuine annuity may lead to risk or harm for the customer – for a sad example see here.

In summary, while other factors must be considered in assessing fairness, correct accounting and transparency about underlying costs are crucial.

Meanwhile, some gospel music

Richard mentioned Mahalia Jackson (who I like a lot).  But here is something just as good, possibly even better.  Sweet Honey in the Rock.

Global warming - thanks for the links

Thanks to everyone who posted on my global warming questions.  It confirmed my view that the science of global warming is somewhat more complicated than the simple explanations suggest.  At some point I will collect together the links to resources, but I don't think that there is (yet) any resource on the web which takes the reader through every logical step of the argument but without being needlessly complex or difficult. The resources which go into detail have massively more than is logically required, and those which are aimed at a less 'technical' audience tend to skip over important logical steps - particularly the move involving the logarithm of CO2 concentration, which is not properly explained in any of the non-technical sources.

Wikipedia would be the ideal place for such a resource, but that has problems of its own (it seems to have a policy that the basic science should not be explained).

Reply to Aquinas on usury

Before discussing Aquinas’ argument against usury, a brief recapitulation. My main thesis is that the scholastic complaint against ‘usury’ was unreasonable, and at best uninformed. This requires understanding what they did mean by ‘usury’, on which Aquinas’ argument in the previous post is very clear. Aquinas did not mean that usury was a form of unreasonable charge against a loan, such as administration costs, or simply very high charges over and above a ‘natural’ interest rate. He was not talking about any form of overcharging. He was talking about any form of charge for the use of money itself. Charging for the use of money is to sell the use of a thing whose use consists in its consumption, and is therefore like selling the same thing twice. It is rather like selling wine separately from the use of wine. It is a form of fraud, and is therefore wrong, he argues.

His argument rests on a mistake. Clearly the use of money is like the use of wine. We consume money by spending it. As Aristotle says “the proper and principal use of money is its consumption or alienation whereby it is sunk in exchange". Money is not like a house, which you can live in, nor a car, which you can drive. Its use consists in destroying it.

But the charge for a loan (meaning the ‘risk free charge’) is not a charge for the use. Rather, it is the difference between the value now of a sum of money to be used in the future, and its value then. Giving £95 to you now, in return of a payment of £100 in a year’s time is simply my purchasing something from you, namely the future £100. The £95 is a payment, not a loan. The loan is the two things together: the present payment, and the contract for a future payment. And the ‘charge’ of £5 is not a charge for the use of the £95, but rather the difference between the future value of the future £100, and its present value, which is exactly £95. Thus it is not a charge for use, and thus we are not selling the same thing twice. Rather, the borrower is selling something to me (the future £100) and I am purchasing it from him at its present value (which is £95). One sale, one purchase, which is how things should be.

Aquinas on usury

Thomas Aquinas discusses usury in a very clear argument in the Summa Theologiae (IIª-IIae q. 78 a. 1). I summarise his argument as follows. He says that it is unjust to sell the same thing twice, but usury is selling the same thing twice, therefore usury is unjust. The minor premiss is proved as follows. Usury is selling the use of money, and demanding the same money back. Now the use of money consists in its consumption - according to Aristotle (Ethic. v, 5; Polit. i, 3), money was invented chiefly for the purpose of exchange: "and consequently the proper and principal use of money is its consumption or alienation whereby it is sunk in exchange". But to sell the use of a thing whose use consists in its consumption, and to demand the same thing back, is selling the same thing twice, therefore etc.

Thomas compares usury to selling wine separately from the use of the wine. This is to be distinguished from renting a house, where the use consists in dwelling it, not in destroying it. To rent out a house is not selling the same thing twice, and therefore not unjust.

The argument seems clear and forceful. But it seems to contradict the conclusion I came to in a previous post, namely that money does have an intrinsic 'time value'. What has gone wrong? More tomorrow.

Are we entitled to the risk-free rate of interest?

Yesterday I asked why there is a risk-free rate at all. Today I shall ask whether we have a moral entitlement to it. You might say that we don't, arguing syllogistically as follows.

1. Getting a risk-free profit is consistently getting something for nothing.
2. You are not morally entitled to consistently get something for nothing.
3. Therefore, you are not morally entitled to a risk-free profit.

In a comment on the previous post, Brandon questioned 2*.  Perhaps there are circumstances when you are morally entitled to receive something for nothing, on a consistent basis?  I shall not discuss this here. I shall simply assume that premiss 2 is correct.  It is the first premiss I am concerned with today.

In defence of the first premiss, it might be argued that investing money at the risk free rate, so that you are guaranteed to get your money back after a period of time, plus an extra component corresponding to the risk-free return, seems like a consistent way of getting something for nothing.  You haven't done anything to get the return, and you ran no risk in doing so.  The only thing that got you the return was the ownership of the principal amount. Thus you have earned something for nothing.

I reply: premiss (1) is trivially false. In the previous post, I argued that the root cause of the risk-free rate is mere time preference.  A farmer wants to sell £100 worth of crop in a year's time.  He sells that future crop to someone now for £95.  Time preference explains the discounting, and the discounting explains the risk-free rate.  And so you are not getting something for nothing. In earning the discounted amount (i.e. the £5) you have to wait for one year.  Thus, the £5 pays you for the waiting.  In lending at the risk-free rate, you are getting something (the risk-free return) for something (waiting until the loan matures). 

As to whether there is a non-trivial sense in which the first premiss is true (perhaps by qualifying 'nothing' in some way - perhaps mere waiting is not a genuine 'something'), I will leave that for Brandon to comment, and I may say something about it later.

Note that modern financial theory only allows two kinds of interest rate, namely the risk-free and the risky rate.  The other kinds that Brandon mentions in his original post (administration charges, social value) are not interest rates at all, at least not in the modern sense.  We should not confuse the various charges and costs built into a loan, with an interest charge itself.

* Or rather, he questioned something like 2.  I'll leave him to comment here if he disagrees.

Usury and the risk-free rate

Yesterday I discussed the efficient market theory and excess risk-adjusted returns.  The theory says you cannot consistently achieve such returns.  However, an 'excess return' means an excess over the risk-free rate.  The risk-free rate is a return that is absolutely guaranteed (because it is risk-free!) and which you can get by lending money over a period of time.  Today I shall examine why there is a risk-free rate at all.  Tomorrow I shall examine whether, given its root cause, we have a moral entitlement to receiving it.

The root cause of the risk-free rate is time preference for money or goods. Would you prefer to have something now, or in a year's time? No one is indifferent to waiting, and everyone would prefer to have something now, rather than later. However, many physical goods we have to wait for, such as a crop. Time preference suggests that the value now of a crop that will be harvested in a year's time will be less than its value in a year's time. Thus if I wish to sell you that crop for future delivery, even if we are agreed that its value then will be £100, its value now will be less than that - say £95.  Banking originally grew out of the practice of selling grain-sale rights at such a 'discounted' price against future harvest, in Lombardy in the Middle Ages.

Note that discounting does not of itself involve lending as such.  We are buying future goods from the farmer with hard cash, who can walk away with the money as his own, with nothing to return. But its implication for lending is obvious.  The 'law of one price' ensures that the risk-free rate and the discount rate converge.  If the discount rate is higher, then I can borrow at the risk-free rate, buy future goods at the discount rate, and make a guaranteed profit.  If it is lower, then I can sell future goods, and invest at the risk-free rate, with guaranteed profit.  If everyone understands this - as the efficient market thesis says they will - the two rates will converge.

In summary, time preference - the preference for value now rather than the same value in the future - leads to discounting.  Discounting in turn (via the law of one price) leads to money having a sort of intrinsic value.  None of this involves any ethical judgment, merely observations or facts about human behaviour.  Tomorrow I will ask whether we are morally entitled to receive this time-value from money.

On usury

Brandon Watson has two fascinating posts here (July 2011) and here (July 2009) about the morality of lending money (‘usury’) and scholastic theories thereof. I raised the question of whether modern financial theory can inform us about this subject, without any satisfactory answer – partly because of the problems of thread formatting, partly because of confusion about the meaning of the terms involved.

Some of the concepts used by the scholastics have a direct counterpart in modern financial theory. For example, damnum emergens, an entitlement to a charge for the administrative costs involved, and periculum sortis, entitlement to a charge covering the risk of the loan defaulting. Two others are much more difficult: lucrum cessans – entitlement to compensation for losing profit that the lender would have certainly had if he had not done the lending, and the view that money on its own never carries an intrinsic title to interest – “money does not breed. It carries no intrinsic potential for profit, and it is immoral and unnatural to treat it as if it did -- 'unnatural', indeed, is the word they often used for it”.

In the following series of posts I will try and make sense of these ideas in terms of modern financial theory. The best place to start would be the efficient market hypothesis. This is the hypothesis that financial markets are "informationally efficient", and that an investor cannot consistently achieve returns in excess of the risk free rate on a risk-adjusted basis, given the information available at the time the investment is made.

Like all theories, it has a theoretical and an empirical aspect. The theory is that because excess returns are so desirable, people will soon find out about them (that’s the ‘informationally efficient’ part), and so competition for them will drive the return down (usually by driving up the price of the investment that yields the returns). Thus, though some investors may find excess returns, they cannot consistently do so. The ‘risk-adjusted’ part involves stripping expected losses from risks to the investment. Some investments may apparent yield excess returns. But once the return is adjusted for the expected or probable loss, it will disappear.

The empirical part is driven by statistical analysis. Louis Bachelier was the first person to propose (in 1900) that stock markets follow a random process. Though his theory was rejected at the time, subsequent investigation seemed to confirm that, if market prices are random, it follows at least that the ‘weak’ form of the hypothesis is true*. One cannot earn excess returns by analysis of past investment prices. The theory is not uncontroversial, particularly after the recent ‘credit bubble’ and subsequent collapse.

The efficient market hypothesis has no ethical component, and involves no moral judgment. It simply posits that there is, in fact, no ‘free lunch’. But there is an associated moral judgment. Our natural view – apparently shared by the medievals – is that a genuine free lunch is somehow wrong or immoral. Unearned income is wrong: everything we get, we should earn, etc. What the efficient market hypothesis suggests is that there is a kind of natural justice. There shouldn’t be excess returns, and in fact – as suggested by the theory and the science –there aren’t.

However, the modern theory diverges from the scholastic one on at least three key points. First, the theory defines excess returns as the risk-adjusted returns over the ‘risk free rate’. The risk-free rate underpins all modern financial theory, and acceptance of it is essentially accepting that money has an intrinsic potential for return, which the scholastics did not accept. Second, the idea that one is only entitled to compensation for losing profit if there was a legitimate profit to be had is somewhat alien to modern financial theory. Third, if the theory is true, then we can reject the notion that lending and investment has to be legislated. The best way of promoting fair lending would be to abolish anti-usury laws.

I will examine these problems in the next post.
*For the semi-strong and strong forms, see the Wikipedia article Efficient-market hypothesis.

Global warming in logical form

I just found this draft paper. I hadn’t heard of Professor Bill Johns before, but his credentials seem respectable, and the paper is fascinating. It summarises the evidence and science behind each of the arguments that carbon dioxide is the main cause of the current global warming. In each case, it finds that the evidence is weaker than appears at first sight. The main arguments are as follows.

1. The Vostok argument. This is named from the Vostok ice core drilled by the Russians through Antarctic ice, and a subsequent study finding a strong correlation between the concentration of carbon dioxide and temperature over a period of 450,000 years. The data is available here. Johns notes that the correlation is striking but does not prove that increasing carbon dioxide causes increasing temperatures (medieval logicians called this the ‘fallacy of false cause’ - fallacia secundum non-causam ut causam). It is possible that the correlation simply results from the fact that when the global temperatures are low, carbon dioxide dissolves in the oceans and its concentration in the atmosphere is correspondingly reduced.

2. The exceptional rise argument. The argument is that the current rate of temperature rise is higher than any rise experienced on Earth for at least 10,000 years. This suggests that industrialisation is responsible for climate change. He concludes, using statistical analysis of earlier changes in temperature over long periods, that there may be something unusual in the current rate of global warming. “However, the statistics give only weak support to the hypothesis that there is something climatically unusual”.

3. The current correlation argument. The argument is that the current correlation between atmospheric carbon dioxide concentration and global warming is significant. Johns concludes that, from statistics alone, there is no reason to believe that the correlation between global warming and increased carbon dioxide concentrations is other than coincidence. “It follows that this coincidence cannot form part of the science supporting the Carbon Hypothesis”.

4. The simple science argument. Much of the support for the Carbon Hypothesis (as our commenter Belette noted) is that mathematical models of climate change predict temperatures rises with catastrophic results (i.e. 3 degrees C or more). Johns argues that mathematical models were originally designed for chemical or physical processes that are well understood, but the physics and chemistry of climate processes is not so well understood. “Modellers do not have a set of similar planets to test their models on, or to evolve their modelling tools”. His comments about the interaction between water vapour (which is the most significant greenhouse gas), and carbon dioxide, are interesting. In the presence of excess water vapour the absorptivity of carbon dioxide is strongly suppressed, and at sea level the contribution of carbon dioxide to infra-red absorption is negligible compared to the natural variability of water vapour concentration in the atmosphere. Thus the science is not so simple.

5. The consensus argument. The IPCC has a number of reliable climate models from which it concludes that there is a 90% probability that carbon dioxide is causing global warming. How can all of those scientists be wrong? Johns notes that few of these climate scientists are “main-stream scientists”, and that most come from a weather-forecasting (meteorology) background. They are not used to formulating and testing models like other scientists because they cannot go back to the laboratory to test the various elements of the model; they have to wait for the climatic conditions to arise that test the models. We should therefore read ‘scientific consensus on global warming’ as ‘meteorologists consensus on global warming’.

Please note that I am simply summarising his arguments. Note also that this is a logic blog. Arguments like ‘X doesn’t understand climate science’ or ‘Y is a global warming denier’ are logical fallacies. From a logical point of view, there are essentially only two replies to an argument of the form “p and p implies q, therefore q”. The first is that p does not imply q. The second is that p is not true.

The London plumbing crisis resolved

Summarising the gobal warming discussion so far. My ‘global warming scepticism’ is simply that the evidence for catastrophic climate change is not clear. A sceptic naturally wants evidence for p or not-p, otherwise (if necessary) he is entitled to be sceptical about both p and not-p. Excluded middle does not apply to propositions embedded in the ‘sceptical about’ operator.

Now, there is a simple ‘textbook’ or ‘idealised’ climate model that can be easily explained, and is clearly nothing to be sceptical about. But this predicts nothing catastrophic (at least not for a long time). Now there is a much more complex model, which involves ‘feedback’ effects. But the problem there, as our commenter says is that “If you want a very simple explanation of how much warming you get from increasing CO2 by Y% then you can't have one: the full theory plus modelling of the earth system is too complex.”

This is a problem for scepticism. If we drop the Fermi assumption that all complex things can be explained simply, and accept that there are some things that are simply too difficult to be explained in a short time, it follows that there will be situations where a sceptic – who is a generalist – is unable to challenge statements made by a specialist. But if unable to do that, he is no longer a sceptic.

One ray of light, however, is that at least one of my several plumbing crises may not be as serious as I feared. A clever site here tells us, for any given rise in sea level, whether our property is flooded or not. It tells me that substantial parts of West London will remain above water even with a rise of 3m. Within 500 years, London may look like Venice. That is something definitely to be welcomed.

How catastrophic is catastrophic?

As there has been no sign of a Fermi explanation so far, I had a go for myself, largely with the help of this paper. Yes, I am aware that Lindzen is widely held to be a climate change denialist and therefore an evil monster, but I admire the way he writes clearly and convincingly and without belittling or talking down to his audience.

The concentration of carbon dioxide has increased since the beginning of the industrial age from about 280 parts per million (ppm) to about 390 ppm.  According to the simple 'textbook' model* of global warming, it is generally accepted that the warming from a doubling of carbon dioxide would only be about 1°C.  That is, the amount of carbon dioxide currently in the atmosphere (about 390 ppm) would have to double to 780 ppm in order to cause a rise in global equilibrium temperature of 1°C.  Simple arithmetic based on the rate of increase in CO2 (see the graph above) suggest that this would take almost 250 years to happen. Furthermore, because of the logarithmic effect - each doubling producing the same arithmetic increase - it would take 250+500 = 750 years to produce a 2°C rise.  This is hardly catastrophic, and gives us some time to do something.  I'll hang on to those incandescent bulbs for now.

But this is much less than current climate models suggest from the warming from a doubling of carbon dioxide.  Why is that?

*To avoid any confusion, I mean the simple textbook model described here as ‘this model’, i.e. where it says “Thus this model predicts a global warming of ΔTs = 1.2 K for a doubling of carbon dioxide.”. 

Arctic meltdown to flood London

I discussed a suitable understanding of ‘global warming’ yesterday, settling on ‘catastrophic man-made global warming’. By extraordinary chance one of the cheaper (in fact free) tabloids this morning was talking about how global warming could cause a meltdown of the Arctic, flooding London. That’s what I call catastrophic! I live close to the Thames, and hardly relish the thought of having to leave the basement for the upper floors, and travelling to Tesco’s by boat, within my lifetime or my children’s.

But let’s move on to reasons for believing in this catastrophe. Clearly the catastrophic flooding will be caused by higher temperatures. But how high do the temperatures have to get, and how will this be caused? What is the Fermi explanation?

On the Road (Carbon footprint)

I just finished 'On the Road' by Kerouac, after a space of forty years. I last read it as a sixteen year old. Had it changed? Yes. Twenty-two year old men to a sixteen year old are gods and giants, whatever they do. To a much older man, they are simply young men. Yet the book gripped me in the same way.

A recurring theme of the book is jazz, and jazz culture (as well as plenty of fast and dangerous driving). Here are two of the numbers referred to in the book. 'The Hunt' by Dexter Gordon - note the comment that says 'I came here after reading On the Road'. (Not me). And 'Congo Blues', which includes some of the giants of 1940s jazz: Dizzy Gillespie, Charlie Parker, the wonderful Teddy Wilson, and Slam Stewart.

"Woo hee!"he yelled. "I'm gonna git drunk tonight". We went back to Frankie and the kids. Suddenly Dean got mad at a record little Janet was playing and broke it over his knee: it was a  hillbilly record. There was an early Dizzy Gillespie there that he valued - 'Congo Blues', with Max West on drums. I'd given it to Janet before and I told he as she wept to take it and break it over Dean's head. She went over and did so. Dean gaped dumbly, sensing everything. We all laughed. Everything was all right.

Note the recording on YouTube is not the same as the one referred to in the book.  Note also that 'Dean Moriarty' (in real life, Neal Cassady) clearly doesn't give a monkeys about global warming, as he races across America at his usual 100 mph in various cars, and in three massive journeys.  Has anyone worked out their carbon footprint?

Definition of global warming

'Belette' commented that I hadn't been consistent in my definition of 'global warming'*.  I had asked for a 'Fermi explanation' showing why it exists, but that requires an understood and agreed definition of what it is.  OK.  There are three ideas locked up in that term, as commonly used and understood.  First, that warming is not a mere accident.  'Global warming' does not mean simply that the earth is hotter than it was some time ago. It means that there is some underlying cause or reason why it is getting warmer, and that as long as the cause exists, the warming will go on.  Second, that the underlying cause or reason is the cumulative increase in carbon dioxide in the atmosphere, caused by industrialisation.  This is properly called 'anthropogenic' global warming, but it usually has that meaning even without the qualification.  Third, that the warming will if unchecked lead to to disaster.  This should properly be called 'catastrophic anthropogenic global warming'. 

The proposition I am sceptical about is there "that increasing atmospheric concentrations of greenhouse gases, notably carbon dioxide, will have catastrophic consequences for mankind and for the planet".  Obvious I don't deny that the cumulative increase in carbon dioxide is causing long-term global temperature to rise.  But no one has explained clearly to me why this should matter.

*Vallicella has just reminded me that he has some definitions here.

Where my arguments for direct reference came from

Someone posted to ask where I got the arguments for 'direct reference' from (For the purpose of this discussion, call ‘Direct Reference’ the theory that part or all of the meaning of a proper name requires the existence of a named object).

Just a question: Who gives this argument for direct reference? I haven't seen it in Kripke or any of the other big names in Phil of Lang. Just curious where you got this specific argument?

The four arguments are listed here. The argument referred to was the first of the four arguments, namely that that a proper name does not signify something that is repeatable, therefore does not signify a property. Therefore it signifies an object. Where did the argument come from? It is loosely based on Kripkean arguments against the view that proper names are non-rigid designators. I.e. I am assuming that 'non-repeatability', which Kripke does not invoke, is close enough to his notion of 'rigidity'.

The second and third arguments are closer to the early modern and medieval discussions of proper names. The fourth argument (that truth-conditional semantics rests on the assumption that the conditions for the truth of a sentence give the sentence’s meaning or significance) was taken almost verbatim from Teresa Marques' "On an argument of Segal’s against singular object-dependent thoughts" (Disputatio, volume II, no. 21, pp. 19-37) although her argument in turn owes much to John McDowell and Gareth Evans.
I haven't replied to the fourth argument yet, due to distractions about global warming and other distracting things.

Global Warming 2: “For details, read the papers”

The title is taken from a comment to my last post about global warming scepticism. That kind of remark is the source of my irritation with the global warmist lobby. They are telling us that everything is very bad, and exhorting me to throw away my stash of incandescent bulbs. But they aren’t given us sufficient reason to believe what they say, other than ‘scientific consensus’ or ‘read the papers’. Here is the comment:

The (surface of the) earth is warmer than if it was just heated by the sun, because it is heated by two sources: the sun and the atmosphere. [This is the inappropriately named ‘greenhouse effect’]. More atmosphere, more ‘greenhouse effect’. For the details, read the papers.

Commenter, this in no way wins you a £5 voucher. A ‘Fermi explanation’ has to be a complete chain of reasoning from cause (or evidence) to effect. Approximations are OK, so are gross assumptions, so long as they are reasonable assumptions, but every link of the logical chain has to be visible. Your comment is wholly useless in this respect. It doesn’t explain the relation between carbon emissions and ‘atmosphere’, nor the relation between ‘atmosphere’ and temperature, nor the relation between temperature and ‘damage’ or ‘harm to planet’. So, no prize, sorry.

On ‘read the article’, about a year ago I got tired of reading stuff about ‘scientific consensus’ and tried to work the whole thing out for myself. It was surprisingly hard. Wikipedia articles like this are a useful overview, but they remind me of those science books I read avidly at the age of 8, how telephones work, how air brakes work, how jet engines work. A useful ‘pictorial overview’, but without depth of explanation. This article is much better, but fails for two crucial reasons. First, it is mathematical. Although the mathematics is not very difficult, there are many people to whom this kind of reasoning is impenetrable. A verbal, or pictorial explanation (or a combination of those modes of explanation) is needed to explain the underlying reasoning, without the maths. The second fault is far worse, because it fails to connect the variable representing the amount of atmosphere, with the industrial process. It neatly explains in a quantitative way how increases in epsilon correspond to changes in equilibrium temperature. But it doesn’t explain how emissions in carbon dioxide are related to epsilon*. Which is what we wanted to know. How much is my stash of incandescent bulbs likely to increase the equilibrium temperature of the earth? Don’t know, and I am keeping the stash for now.

*To be fair, the article does state this implicitly, in the bit where it says “The radiative forcing for doubling carbon dioxide is 3.71 W m−2”. But it doesn’t explain where that figure comes from, nor does the article http://en.wikipedia.org/wiki/Radiative_forcing it links to. And it only gives figures for carbon dioxide emissions. As I mentioned in the previous post, carbon dioxide is not the only greenhouse gas.