As we have possibly seen so far (and the examples can be multiplied, of course) truth is a difficult, although not impossible, thing to seek. Truth is probably more elusive than science would have us believe, but hopefully is less elusive that some of the extreme versions of postmodernism that exist would have us think.
In the previous posts we have travelled a long way in one sense, but not very far in another. We have suggested, for example, that science does not lead us towards the truth particularly more than any other subject, because the truthfulness of science, or at least physics, depends on an arbitrary metaphysical truth that, say, forces used in calculation are ‘real’. While this is generally accepted to be the case, we have to concede that it is not necessarily so.
Another approach, which appeals to some minds, is to doubt everything. The master of this was Descartes, who doubted everything and anything until he came to something he could not doubt. The presentations of his senses, famously, were doubted, as he could be a brain in a vat and the sensations could be being fed to him by an evil demon for its own amusement. Memory also plays us false, as we know. It is well known that Descartes came up with the idea that what could not be doubted was the fact of his thinking ‘I think therefore I am’.
This expression (or its Latin form: cogito ergo sum) has resonated down the philosophical centuries. Some have accepted it, some rejected it, and some tried to modify it. Hence we can find criticisms that Descartes, in fact, assumed too much. Perhaps, it is suggested, Descartes could only say ‘There is thinking going on’ – the cogito assumes the identity of the thinker. Again, perhaps, as someone once suggested to me, he lacked enough doubt, and should have said ‘I think I think, therefore I think I am, I think’. But maybe we are looking through the wrong end of the telescope here.
The physical sciences rather follow Descartes’ method. Nothing is accepted except what can be shown to be the case. Reductionism (for that is what the physical sciences do) aims to reduce things to their components, understand them and then reconstruct the original, more complex structure. It sort of works; we can try to understand an electron in free space, and then an electron in an atom. The two in fact behave very differently, and so reductionism only sort of works. But we can proceed to atoms as a whole, molecules and hence organisms. At each level, however, extra phenomena occur which cannot be explained by the components of that level alone. Hence biology is biology and not a branch of chemistry; chemistry is chemistry and not a branch of physics.
The other issue with Descartes is that we do not actually strip most things down to their essentials, or to things we cannot doubt. As children we learn from the things we see, hear, touch, smell, and taste and so on. We do not doubt what is presented to our senses and work on how they fit together – that which glows is hot for example, or that knives are sharp and can hurt. Reductionism only takes us so far.
The other end of the telescope to peer down is perhaps best described by Newman: ‘I would rather have to maintain that we ought to begin with believing everything that is offered tour senses, than it is our duty to doubt of everything’ (Newman, J. H., An Essay in Aid of a Grammar of Assent (Assumption Press, 2013 [1870]) p. 246, or p. 377 in the original).Newman argues that believing everything until shown otherwise is the true way of learning – we discover the truth and discard errors along the way. Thus a child on a train might discover that when they stick their thumb in their mouth the lights go out as the train enters a tunnel. Repeated experiments may convince the child that the original observation was a coincidence.
Newman’s point is thus at the opposite end of seeking truth than Descartes’. Our senses are, on the whole reliable, according to Newman and we can arrive at decent understandings of that which is the case via them. Descartes disagrees: our senses, which can be unreliable, therefore cannot be relied upon and we have to find another basis for our beliefs and ability to live in the world. Descartes has to seek a ‘bridge’, a means of getting from the reliable ‘in here’ self to the real ‘out there’ world without using the senses. His answer, famously, is God who is ultimately reliable.
Newman’s point is, perhaps backed up by Plantinga who argues that there is an evolutionary reason why our senses are reliable. Our sensing of human-scale objects is, on the whole, reliable. After all, if early man had to consider the reliability of her senses before running away from the sabre-toothed tiger, they would probably have been a lot fewer early people around. Similarly, if we had to justify every memory of a large cat type creature with big teeth before recognising it as a sabre-toothed tiger and taking appropriate action, the tiger would have been far better fed. As Plantinga comments ‘Beliefs about where I was yesterday are ordinarily far more likely to be true than the latest high-powered scientific theories.’ (Plantinga, A., Where the Conflict Really Lies: Science, Nature, and Naturalism (Oxford: OUP, 2011), p. 313).
The point is this: at human scales, our senses, memories and so on are likely to be reliable, and we tend to assume they are (even Descartes ate and drank without too much interrogation) . If they prove not to be we are surprised and might seek a reason – a cleverly drawn picture, for example, is an optical illusion. When we spot the way it is drawn, we have an explanation. At the scales of the very big and very small or very complex (galaxies, atoms, the internal workings of organisms, for example) our senses prove to be inadequate and need augmenting. That is not the fault of our senses, because in day to day life the very big, very small and internal do not worry us particularly.
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