The Cogito. The Story So Far! Descartes’ search for certainty has him using extreme sceptical arguments in order to finally arrive at knowledge. He has rejected the senses through the argument from illusion. He has used the dream argument to show that we cannot tell dream from reality – so sense experience unreliable. Adds the evil demon hypothesis to show that even our a priori concepts are unreliable. A position of total scepticism! Descartes is a drowning man at the start of Med 2 – searching for Archimedean point – foundation point.

The Cogito. The Concept. (1) Descartes now realises that even if an evil demon controls the concepts in his mind there must be a mind for the demon to control in the first place. I think, therefore I am….Cogito ergo sum. Evil demon cannot fool a fictional, non existent being…there must be a real consciousness to be fooled. Descartes now identifies his essence with thinking – “what kind of thing am I – a thinking thing”. (Med 2) So a priori knowledge – of being a thinking thing – is the foundation point – the Archimedean point he was looking for. Let him deceive me as much as he likes, he can never cause me to be nothing, so long as I think I am something…..the proposition I am, I exist … is necessarily true every time I express it or conceive it in my mind.

The Cogito. The Concept (2) The cogito satisfies the necessity and sufficiency criteria for a statement being true. This means thinking is necessary if we are to say there is existence – it would be impossible surely to say we are aware of our existence without being aware at all! In fact to deny the point above would involve a self contradiction! It means that thinking is a sufficient reason for claiming that we exist. As long as we have thinking then surely, even if there’s nothing else to us, we exist.

The Cogito. Analysis (1) The Cogito is really a syllogism. Aristotle developed syllogisms. One criticism suggests that the Cogito is dependant upon a hidden premise and that Descartes is not entitled to rely on the content of the hidden premise. I am thinking (premise 1) Everything that thinks exists (premise 2) Therefore I exist (conclusion) But remember the evil demon is in control – there may be no other beings – Descartes is in a solipsistic universe – all on his own! So there can be no premise 2 can there?

The Cogito. Analysis (2) Another criticism has to do with the relationship between thinking and existing. Is Descartes suggesting that it is only when mental activity is going on that existence is guaranteed? What happens when there appears to be no conscious mental activity? Is Descartes suggesting that there is always mental activity going on. Cognitive research would support him in this. So would meditation practice. Question is – does Descartes mean to so closely link perpetual thought to existence?

The Cogito. Analysis (3) Another criticism would question the link between thinking and the existence of the self. Both the Buddha and the Scottish Empiricist philosopher David Hume made the same point:- When we investigate the workings of the mind we find thinking – an endless series of interrelated thoughts – but not a thinker or self who does the thinking. So thinking does not necessarily mean thinker – a self that exists!

The Cogito. Analysis (4) Some contemporaries of Descartes suggest that he does not clearly explain what exactly he means by thinking and by existence. Another criticism from his contemporaries is to say that in choosing thinking to be equated with his essence – “I am a thinking thing”, he is making a mistake. We wouldn’t say “I walk so I am the walking” would we, or “I eat so I am the eating”? Another criticism is that while in the apparent control of the evil demon Descartes assumes that reason still functions but the whole point of the evil demon hypothesis is to undermine the reliability of reason. The evil demon can interfere with any mental process.

The Cogito. Analysis (5) Assume the cogito is sound. Descartes has indeed found his Archimedean point – from this he intends to build up certainty of knowledge and overcome scepticism. But how is he to move from this “solipsistic certainty” to establishing any other fact? The cogito is sound but a cul de sac – a dead end. How does he move from the certainty of the existence of a thinking subject to proving the outside world?

The Cogito. Analysis (6) Descartes’ response is to use the “clear and distinct” nature of the cogito to establish a rule:- Whatever is clear and distinct is to be trusted – this will allow us to build on the Cogito. But “clear and distinct” feelings can be wrong – hypnosis and madness give us “certainties” that are wrong! This path out of the Cogito is blocked? Equally Descartes’ response to the hidden premise criticism is based on the existential/gut certainty of “clear and distinct” perception but if the “C & D” is untrustworthy we are no further forward.

The Cogito. Conclusion. Cogito is convincing. Psychological, logical and existential certainty that thinking and existence are bound together. Hume and the Buddha are irrelevant – Descartes has related thought to existence regardless of nature of “self”. To suggest that “walking”, “eating” are to be as strongly related to our essential nature as “thinking” is wrong for we may not eat or walk and yet still be “us”, but not without “thinking” surely. It appears humans are constantly cognitively active – even in coma – so the point that we may not exist if not thinking is irrelevant too. Remaining weakness is where do we go with the Cogito – it appears to be a dead end.