Dr Vallicella has a post about intentionality here which reminds me I haven’t addressed the question of when two people are having thoughts about the same individual.
I characterised intentionality in this series of posts and particularly this. I have argued that it is merely a semantic phenomenon: certain verbs are ‘logically intransitive’ – they have a grammatical accusative, but no logical one. ‘Tom wants a cigarette’ has the grammatical subject ‘Tom’ and the grammatical accusative ‘a cigarette’. But, unlike ‘Tom is smoking a cigarette’, the sentence is consistent with ‘nothing is a cigarette’. Thus the verb ‘wants’ is logically intransitive. I also argued that we can parse a sentence like ‘Tom has a thought about a hobbit’ in two ways. First, as
Tom / has a thought about / a hobbit
where the verb phrase ‘has a thought about’ is logically intransitive (it appears to relate two objects: Tom and a hobbit, but clearly it can’t, as there are no hobbits). The other way of parsing it is
Tom / has / a thought about / a hobbit
where the verb ‘has’ relates Tom and a thought. This is logically transitive, given that there are such things as thoughts, and given that Tom can be related to his thoughts by thinking them. That suggests we can analyse any sentence containing a logically intransitive verb phrase into a sentence containing a logically transitive one. If possible, that would explain intentionality completely. But what about
(*) Tom has a thought about Frodo ?
It seems easy to explain a thought ‘about hobbits’. It is a thought we would express using the word ‘hobbit’, or which would involve the attributes we commonly attribute to hobbits (being short, having furry feet, being prone to finding magic rings etc). But Frodo? How do we explain the possibility of two different people having a thought about the same individual fictional character, without being drawn into Meinong’s junkyard of non-existing objects?
To resolve this, I shall invoke two principles. The first is the ancient view that thought is a form of silent speech which, if expressed, would signify to the thought to another. Since signification is in some sense public – many people can grasp the meaning of speech, which is indeed the whole point of language - this resolves the apparent problem of thoughts being unobservable or inaccessible. The second is that the term ‘thought of X’ is true of any thought which, if expressed, would contain a term synonymous with ‘X’. I.e. ‘Tom has a thought about Frodo’ is true iff Tom has a thought which, if expressed, would contain a term synonymous with the name ‘Frodo’ as it occurs in ‘Tom has a thought about Frodo’.
Thus the apparently intractable problem of explaining when two thoughts – scientifically unobservable events – can be reduced to the simpler problem of explaining when two proper names have the same meaning. More tomorrow.