Descartes’s dictum; Cogito ergo sum, is oft quoted and usually misunderstood. What Descartes was trying to say was what is known as Cartesian ‘doubt’, expressing doubt on the question of reality. How do we know what is real? How do we know that our perception of an external reality is not just a figment of our imagination – a hallucination or no more than a daytime dream? Descartes even went so far that there was a malevolent demon assigned to everyone, whose job it was to deliberately lead us astray, deceive us in our perception. To pursue this problem further, Descartes asked "is there anything that I can be sure of?" Yes, the fact that no matter what the malicious demon could do, the fact that Descartes was thinking about this was indisputable – hence ‘I think therefore I am’ (Cogito ergo sum).
Descartes was then able to go a little further, having accepted doubts about the sensory perception of the material world and expressed it as the Cogito, Descartes realised that none of the apparent features of the human body was necessary in the this process, so all that is left is thought itself, so Sum res cognitans: ‘I am a thing that thinks’.
Now you might think that Monsieur Descartes was now still ‘locked or trapped inside’ his body with no more than the contents of his mind (which may or may not be distorted by the ‘malicious demon’). However the clever Mr Descartes realises one concept that he has, along with everyone else, is the concept of God. The concept of God is Descartes’s ‘Get out of prison’ card. His actual argument, or 'proof', of God’s existence is somewhat specious (more or less running along the lines of St Anselm’s ontological argument), however Descartes’s God is a Christian God and Descartes’s successive reasoning runs roughly as follows:
“Because God created me and is benevolent, he is concerned with my intellectual welfare as well as my moral one. If I do ‘my bit’, then God will validate the things which I am very strongly disposed to believe. Now I find that however much criticism I make of my ideas, however carefully I think out what is involved in my beliefs of the physical world, although I can suspend judgement in the doubt (I wouldn’t have got to this point if I could not), I do have a very strong tendency to believe that there is a material world. And since I have this disposition and I have done everything in my power to make sure that my beliefs are not founded in error, then God will at the end make sure that I’m not fundamentally and systematically mistaken. That is, I can rightfully believe that there is such a (material) world”.
(Quoted with very slight modification from Brian Magee, ‘The Great Philosophers’, OUP, 1987, ISBN 0-19-289322)
Clever Old Descartes! This is what comes of staying in bed until midday (Descartes’s modus operandii).
Now I ought to go and play some ‘intellectual’ music, something like: Schoenberg’s, Verklarte Nahct’ perhaps. No, on second thoughts it will be Ian Dury and the Blockheads, ‘New Boots and Panties’ (steady Marco, steady…). This says just as much about the human condition as anything else.