Wednesday, February 22, 2006

Rain tomorrow

"There is some actual state of affairs which constitutes its now being the case that it’s possible that it rain tomorrow"

But is this actual state of affairs is the same state of affairs as the state of affairs which will obtain when it rains tomorrow? This seems to be the argument.

1. A statement must be true or false, and so there must be conditions under which it is true.

2. To state the conditions when a given proposition is true, is to say what IS the case, if it IS true. Merely to state the truth conditions is to specify something that exists now.

3. Thus statements about the future can be reduced to statements in the present tense. For if the truth condition obtains, the statement that it obtains, is true now. If it does not obtain, the statement that it does not obtain, is true now.

But why should the truth conditions be in the present tense? I agree that a proposition like 'Tom thinks it will rain tomorrow' says something about the present. It says that Tom has a certain thought, right now, in the present. Similarly 'the weather forecaster says it will rain tomorrow' says something about what the person on the TV says, now. Likewise 'It is causally determined that it will rain tomorrow'. Similarly also for 'it is possible that it will rain tomorrow', which says something about the speaker's present state of knowledge.

But 'it will rain tomorrow' doesn't say anything about the present. 'It will rain tomorrow' is true if and only if it WILL rain tomorrow.


Edward Ockham said...

There seems to be a contradiction here. On the one hand you seem to agree with me that the proposition expressed by 'it may rain tomorrow' is irreducible to the present tense. On the other hand you say 'propositions asserted now, if they are made true by some state of affairs, are made true by some "actual" state of affairs.' When you say 'made true by', are you simply asserting a causal connection? You mean there is some actual existing state of affairs that is not itself equivalent to its raining tomorrow, but will cause the rain to happen.

If so, do you think that this state of affairs WILL cause it to rain, or that it IS causing it to rain?

We should also distinguish the state of affairs that grounds our assertion that it will rain, from any state of affairs that will cause it to rain.

Edward Ockham said...

To get round the difficulty that present events may cause future events, suppose I have a quantum probability generator that uses sub-atomic quantum effects to generate completely random events. I then use these to seed clouds and cause rain randomly, in an area that does not normally have rain. Then what makes the proposition 'it IS true that it will rain tomorrow' true? Nothing that causes rain tomorrow, for that is a random event.