Let me jump to about 1637 AD for another example of the pottiness of Philosophy: ‘Cogito ergo Sum’ – ‘I think, therefore I am’ – wrote Descartes. Descartes couldn’t convince himself he existed till it occurred to him that he was thinking! Therefore he must exist! Did he really think as an adult person that he couldn’t believe he existed until the logic of words proved it?
He later changed his mind completely, and said he can after all trust his senses that he exists, and discarded Cogito ergo sum! He is famous for the Cogito but he discarded it.
His initial argument that he can’t trust his senses, because they had sometimes let him down (see below), is feeble; and his later proof that God exists, derived from Anselm, is even more so. It is a litany of opposite opinions, and of silliness of argument.
Philosophers have written about him that he was sceptical to the point that he couldn’t trust the philosophizing of the previous 2000 years. None of it gave him absolute certainty. He wished to start all over again with a self-evident axiom he could be absolutely certain of, and then work forwards from that by deductive logic to establish other certainties as in mathematics. This was his ‘methodological scepticism’, or what he called his ‘mathematical method’.
‘Cogito ergo Sum’ didn’t lead him to the conclusion that he, as body and mind, existed. It was only his mind, which was doing the thinking, that existed! And from that logical certainty, and only from that, did he think he could ever arrive at other truths, and by way of logical deduction. He couldn’t trust what came to him through his senses because his senses sometimes proved wrong. So he couldn’t believe that his body existed because his senses may be fooling him that he had arms and legs.
I find it difficult to credit Descartes with having such thoughts, and therefore difficult to lodge them in my mind. They seem so pottily rationalistic to the point of irrationality that none of it follows. So I may well have got his thoughts, and their sequence, not exactly correct in what follows below.
Descartes saw that his senses sometimes proved wrong. For instance, honey was runny when warm, solid when cold, yet was still honey! Descartes also reasoned that what came to him through his senses might be in a dream; or that God or a wicked demon might be deceiving him in his sensations. But, even if a demon were deceiving him, his mind would still have to exist for this demon to be deceiving it (see here.)
(But, as I think Ayn Rand pointed out (in a site dedicated to her admiration and criticism of Philosophy), we all rely on our senses to correct the few occasions when our senses temporarily deceive us.)
Subsequent philosophers have taken ‘Cogito ergo sum’ not simply as Descartes making a logical inference from the fact of his thinking to the existence of an agent doing the thinking. They think also that he regarded ‘Cogito ergo Sum’ as ‘the certainty of first-person experience’ — which can be paraphrased as ‘intuition of his own reality’ or ‘logical self-certification of self-conscious awareness in any form’ (from www.philosophypages on Descartes but I can’t now trace precisely where on this site.)
This all seems to mean that Descartes had an intuition, separate from his logic, that he, or rather his mind, existed! (Whatever next are philosophers going to think of!)
It seems that Descartes himself wrote that ‘I am’ is an immediate intuition and not the result of a line of reasoning about which he could be deceived; therefore it is certainly true , presumably because it is a clear and distinct perception, from here. This seems to mean that he could trust his senses that he, as mind and body, existed. (To me however, Cogito ergo Sum is an argument. In fact, Descartes did later write that the Cogito is a syllogism whose two premises are ‘I think’ and ‘Whatever thinks, must exist’.)
So, in the above paragraph, I touch on Descartes coming to believe in the perceptions of his senses, which is in direct contradiction to ‘Cogito ergo sum’.
It has been pointed out (here) that Descartes at the Cogito stage of his philosophizing could be defined as an ‘epistemological idealist’ in that he was sure only that his mind existed, and that the external world was just an idea or picture in that mind and may not really exist at all.
It seems some modern philosophers are still worrying whether his Cogito ergo Sum is actually fully logical.
How cretinous it is that all this counts as Philosophy!
The way I’ve presented Descartes’ arguments may not be true to his life and the order his arguments came to him.