Friday, September 14, 2012

Fatalism and determinism; theories of perception

To: Alistair L.
From: Geoffrey Klempner
Subject: Fatalism and determinism; theories of perception
Date: 7th May 2008 12:07

Dear Alistair,

Thank you for your email of 22 April, with your notes on unit 9 of Possible World Machine, and your third essay, in response to the question, 'Compare the theory of fatalism with the thesis of determinism. Is there any way that one could consistently hold a determinist view while denying fatalism, or hold a fatalist view while denying determinism?'.

Thanks also for your email of 6 May, with your notes on unit 10.

Unit 9 and essay

I'm dealing with these together as the same theme runs through both. Possibly, I overestimated the obviousness of the irrelevance of fatalism of the 'divine intervention' variety (the story of Oedipus is a case in point, where the gods will see that the Delphic oracle's prediction will be upheld come what may). I don't find this form of fatalism interesting. If 'someone up there' is determined that X will happen, regardless of what I do, that is not a belief that is amenable to philosophical critique.

By contrast, the fatalism in question is the variety which is fully consistent with determinism (although it does not entail determinism) and does not require divine intervention to outwit me.

However, there is a fallacious argument which makes it seem as though divine intervention magically comes into play. If I am going to be run over by a bus in one minute's time then I am going to be knocked down even if I don't get up from my desk (I'm on the first floor, facing the back of the house in case you were wondering.) If I am not going to be run over, then I am not going to be run over even if I deliberately run out into the main road and throw myself into the path of the next number 76 to Low Edges.

The argument must be valid, because it relies on a theorem of classical logic:

P -> (Q -> P)

This is actually one of the so-called 'paradoxes of material implication'. We find it paradoxical that if P then irrespective of any Q you might choose, if Q then P.

Q can even be -P.

However, no-one would be tempted by the argument, 'If I am going to be run over then even if I'm not going to be run over then I am going to be run over'!

Philosophical fatalism (henceforth, 'fatalism') is a worth while target and far more difficult to refute. The philosophical fatalist accepts that my decision is also fully part of what 'was to be'. The effect of fatalism is the same as determinism: it denies my sense of being an agent, of being 'in charge' of what I do.

However, there is an important difference, and this was what the essay question was intended to bring out.

Fatalism can be true even in a world where determinism is not true. To see this, imagine a godlike observer who sees the future. Past, present and future are already fixed. Determinism is not required. (I think you have seen this point.)

On the other hand, determinism, if it holds, is simply a truth about how things stand now. Someone who denies fatalism can argue that it is logically possible that tomorrow the law of determinism will cease to be true. It is irrelevant that we believe that the laws of nature never change. That is just an empirical belief, and a non-logical truth, if it is true.

Getting down to the nitty gritty, however, determinism and fatalism attack my sense of being an agent in different ways:

-- The fatalist says, 'Everything I do is just something that happens.'

-- The determinist says, 'Everything I do is just something that is caused.'

One response is to argue that there is no inconsistency in an action of mine being something that 'happens' as part of the course of nature, nor in particular in its being something that is 'caused'. This is the compatibilist argument discussed in unit 2.

However, fatalism unlike determinism arguably makes an incoherent claim; this is what I tried to bring out in the second dialogue. It is arguably nonsensical to talk about a proposition about the future being 'true now'. The temporal indexical 'now' adds nothing. All one is left with is, 'If P, then P.' There is no way to coherently state the 'belief' in fatalism. You can't extract a metaphysical proposition from a mere tautology.

Unit 10

Eddington's 'Nature of the Physical World' which was very popular in its day (my father had a copy) is typical of the view which once prevailed -- and possibly still does -- amongst physicists: that I am wrong to think that this desk is 'solid', and that nothing in the external world is at it seems to be.

Russell enthusiastically endorsed this view when he argued, 'Naive realism leads to physics. And physics, if true, shows that naive realism is false. Therefore naive realism is false.' ('If naive realism is false, then if it is true then it is false' is an instantiation of the theorem quoted above.) (I think the reference is in 'Problems of Philosophy'.)

It is against this, that one would deploy the point about 'medium sized objects' and the logical connection between the concept of perception and human agency, which you are onto in your account of a capacity to 'model' the world which we have evolved for practical purposes.

This is realism about perception (and direct realism, not a representative realism which puts us behind a veil of perception) but it is not 'naive' realism. On the contrary, the arguments in its favour are philosophically sophisticated. The upshot is that we do, in fact, see things as they are. Grass really is green. It is irrelevant that one has an explanation in terms of cones in the retina and different light wavelengths. All that may be true, but does not undermine our normal perceptual beliefs.

The worry about an 'illusion created by non-material minds' is a different point, which goes back to Descartes' 'evil demon' argument from the first Meditation (to which Berkeley responded by turning Descartes' argument upside down -- there is nothing to be sceptical about because there's nothing God can do to make 'matter' exist).

I'm sorry, I don't have any specific references about 'scale' in relation to the philosophy of perception. David Hamlyn 'Sensation and Perception' (RKP, unfortunately out of print) is an excellent book on the history of theories of perception.

Historically, the first effective defence of non-naive, non-representational realism about perception came with the 'new realism' in the first part of the 20th century, in particular in the work of the much neglected philosopher Samuel Alexander ('Space, Time and Deity'). Unfortunately, much of the gains were lost with the rise of logical positivism and phenomenalist theories of perception. It wasn't until the 50's, with the rise of 'ordinary language' philosophy in Oxford and in particular J.L. Austin ('Sense and Sensibilia') and Wittgenstein's later work at Cambridge ('Philosophical Investigations') that a better, more sophisticated defence of realism was developed.

There is a strong temptation to think that an account of perception depends on empirical investigation into the processes 'behind' what we see, both in the external world and in our own bodies. You've said a number of things that depend upon what scientific investigation has discovered about how visual perception works.

A good question to ask -- in the spirit of an investigation into possible worlds -- is how differently alien beings could be constituted and yet still perceive things 'as they are'. If they are the same size as us, and have roughly the same interest in satisfying needs and avoiding harm, then it not beyond the bounds of possibility that we could agree about much of what we see even if our internal processes are very different. That shows something.

All the best,

Geoffrey