Cartesian Rationalism:The Cogito

Meditation 2 and onward…

Putting the Demon back in its Bottle• Successful method?

– is Descartes’ method of doubt a useful and thorough tool to eliminate uncertain beliefs?

– …or a useless project that takes doubt too far and out of context?

– …it may rule out the possibility of error…– …but is any of our knowledge rescuable?

• Descartes’ difficulty: – unless he can find infallible foundations for

knowledge, infallibilism will lead only to scepticism…

– Goldman: ‘A major task…is to show that there is some such set of self-warranting propositions that support external-world propositions.’

The Cogito Cogitated

‘this proposition, I am, I exist, must be true whenever I assert it or think it.’

• Can you conceive of any difficulties here?– Any qualifications?– Any undefined terms?– If you can think of difficulties, what follows for

infallibilism?

Descartes’ First Certainty: The Cogito

• the Evil Demon argument cannot generate doubt about my own existence or the fact that I am thinking. – …Not even an all-powerful evil genius can make me think that I

exist when I do not exist. – This would require making me exist and not exist at the same

time, which is impossible. – And not even an all-powerful evil genius can make me think that

I am thinking when I am not thinking. – This would require making me think and not think at the same

time, which is impossible.

The Cogito: a ‘self-warranting proposition’

• Formulations:– Cogito ergo sum – first (Latin) version of ‘The Meditations’– I think therefore I am – English translation of the Latin– ‘I am, I exist, must be true, whenever I utter or conceive it in my

mind’ – English translation of first French version.• Descartes suggests the latter (in another text):

• “When someone says “I am thinking therefore I am, or I exist”, he…recognises it as something self-evident by a simple intuition of the mind.”

• So, Descartes intends the Cogito to be a self-verifying act of intellectual intuition: Its truth becomes apparent through the act of performing it: ‘I am thinking, therefore I exist.’

• It is often called his ‘First Certainty’ for this reason.

Issue 1 Issue 2

Issue 3 Issue 4

Issues with Descartes’ intellectual intuition: if true, time-limited

• The Cogito is a very limited proof: ‘I am, I exist, must be true, whenever I utter or conceive it in my mind’.

• …you only exist for as long as you are performing the Cogito?

• ‘It will be true only if I think it and only so long as I think it.’

• So, the proof of self-existence expressed by the cogito is temporary…– But Descartes thinks that even a

single moment is enough…

Existence only in the gaps between ?words?Rene Magritte, ‘The Blank Chart’, 1961

Issues with Descartes’ intellectual intuition: Lichtenberg, grammar, absence of self

• Deep vs surface grammar: e.g. most nouns are (proper) nouns, and label things. What do abstract nouns label?

• Not all nouns refer to actual objects…• Compare

– ‘Eric runs’ – there is a subject, running.– ‘It rains’ – is there a subject, raining?– ‘Eric thinks’ – there is a subject, thinking.– ‘I think’ – is there a subject, thinking?

• Georg Lichtenberg (C18 physicist, aphorist): ‘“It thinks”, we really ought to say, just as we say, “It thunders”’.

• We assume the sentence ‘I think’ has a subject…does it?

mouse – an actual object

mousiness – not an actual object

Issues with Descartes’ intellectual intuition: (The underlying picture of) the Cartesian Theatre is weird

Issues with Descartes’intellectual intuition: Humean bundles, limited selves

• Can Descartes claim that he has an immediate, unmediated, non-inferential perception of himself?

• In opposition to Descartes, David Hume says that whenever he tries to perform the Cogito, he has no certain consciousness of himself…– “For my part, when I enter most intimately into

what I call myself I always stumble on some particular perception or other, heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe anything but the perception.” (Treatise, I,iv,6)

• For Hume…the self is just a bundle of sensations• You are merely…a collection of thoughts

Intellectual intuitions summarised…

• Descartes (arguably) thinks that the Cogito is a moment of pure a priori intuition or demonstration…– His ‘Archimedean Point’– The foundational, non-inferential justification-condition which

allows a key knowledge-claim to be made…– Because of the Cogito, fundamental claims about what

exists/can be known can be grounded in and justified by infallible a priori intuition and/or demonstration.

– And through further steps based on the Cogito, Methodological Doubt can be arrested and the Evil Demon and Dream arguments defeated

• Key problems with the Cogito remain, even if true: – Arguably it is a proof only of flashes of self-existence – Arguably it does not prove the existence of a classically

conceived self or ego

Next steps: Clear and Distinct Ideas

• Even if the Cogito is only performed for an instant it is indubitably true whilst it is being performed.

• It is a ‘clear and distinct idea’:– “I call 'clear' that perception which is present and manifest to an

attentive mind…”– I call 'distinct', that perception which, while clear, is so separated

and delineated from all others that it contains absolutely nothing except what is clear“.

– “If we give assent only to those things which we clearly and distinctly perceive, we will never accept anything false as being true…”.

• So: C&D = T!

Next steps: The Trademark Argument

• Another clear and distinct idea (=rational intuition) we have is that of God– We have the idea of God within us – He has placed his ‘trademark’ on us.

• Ideas are copies of originals which are greater still. And a trademark implies a maker.– So God must exist, to have originated the idea of him / to have

placed his trademark.• And God is not a deceiver: so anything we perceive

clearly and distinctly is true.• So we can trust our senses if we check our sensory

experience using our rational intellect…

Brief paired writing tasks

1. Explain Descartes’ Cogito argument2. What issues with his conception of self

are there? 3. What characterises Clear and Distinct

ideas?

Descartes’ Reconstruction of Knowledge

1. I can only know what is infallibly justified and therefore true.2. Cogito is true. What qualities does it have?3. [Clear and Distinct Ideas] The Cogito is a clear and distinct idea,

which means it is true (as it is guaranteed by God, whom I perceive C&D to exist).

4. What other ideas are clear and distinct ( = true) within me?5. [Trademark Argument]…The idea of God is clear and distinct within

me, and this idea is so perfect I cannot have placed it there, so it must have come from God.

6. Hence God exists and is not a deceiver. 7. Thus the Evil Demon and Dreaming Arguments are not correct. 8. And many of my perceptions of everyday objects are clear, and

when they are known through intellectual judgement also, they can be distinct.

9. Hence as long as I am careful to judge my sensory evidence rationally I can trust the evidence of my senses and avoid Error and Illusion