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?
But, he later changed his mind completely, and said he could after all trust his senses that he exists, and discarded Cogito ergo sum! (see Descartes 2 on this site.) He is famous for 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, see here. That God exists leads to the conclusion that he can trust the senses that He gave him. It is a litany of silliness of argument.
Philosophers have written about Descartes 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 further from it by deductive logic, to establish other certainties as in mathematics. This was his ‘methodological scepticism’, or what he called his ‘mathematical method’. (Didn’t he consider the philosophers of the previous 2000 years to have been as rigorous truth-seekers as he was himself?)
‘Cogito ergo Sum’ didn’t lead him to the conclusion that his mind and body existed. He couldn’t believe that his body existed because his senses may be fooling him that he had arms and legs. His senses had previously sometimes fooled him. From Cogito ergo sum, he could only deduce that his mind, which was doing the thinking, existed! And from only that logical certainty, could he ever arrive at other truths, and by way of logical deduction.
These thoughts of Descartes seem to me pottily rationalistic to the point of irrationality. So I may well have got his thoughts, and their further sequence, not exactly correct in what follows below.
An example for Descartes of his senses proving wrong was that honey was runny when warm, solid when cold, yet was still honey! Descartes also reasoned that it was possible 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 sBut no, it seems rather that what Descartes meant was that clear and distinct perceptions by the senses can’t be wrong, and he came to believe this after proving to himself that God existed and that the God-given senses can’t be wrong.ensations. 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, who took philosophy seriously, sanely pointed out: we all rely on our senses to correct the few occasions when our senses temporarily deceive us.)
The Cogito, as described above, adds up to meaning that Descartes made a logical inference, from the fact of his thinking, to the existence of an agent doing the thinking. That’s pretty obvious!
But subsequent philosophers go further and say that Descartes also thought of it as meaning ‘the certainty of first-person experience’ or ‘intuition of his own reality’ or ‘logical self-certification of self-conscious awareness in any form’ (This comes from http://www.philosophypages.com/ 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 logicking, that 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. It seems that wth this, Descartes was accepting the reliability of his senses, rather than deriving all Truth from ‘I think, therefore I am’. It implies that he came to believe in ‘I am’ as an immediate intuition not needing ‘Cogito’.
So, it seems that Descartes came to believe in the perceptions of his senses that he, as mind and body, existed, which is in direct contradiction to ‘Cogito ergo sum’.
Descartes did however later write that the Cogito is a syllogism whose two premises are ‘I think’ and ‘Whatever thinks, must exist’. But it seems that, even within this thinking, some modern philosophers are still worrying whether his Cogito ergo Sum is fully logical!
How idiotic that all this, including my own small arguments, count as ‘Philosophy’!
It has been pointed out (here) that Descartes at his Cogito stage 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 on its own at all. Phew, that’s Philosophy!
The way I’ve presented Descartes’ arguments may not be true to the actual sequence they came to him in his lifetime.