Remember the reductio in 42/43 VOL 2
If the cogito is doubted then it is thought
If the cogito is thought then it is believed to be true
Therefore: if the cogito is doubted, then it is believed to be true.
(This is a hypolitcal syllogism)
Argument 2 (Enthymematic):
If the cogito is doubted, then it is believed to be true
If the cogito is believed to be true then it cannot be doubted
Two ways to understand the inability to doubt:
The [denial of the cogito] is selfcontradictory
I think but do not exist
This is NOT contradictory thought – it is a synthetic statement and not an analytic one
(Synthetic statements means is it not synonymous)
The [denial] of the cogito is selfcontradictory
What Descartes is saying is that the ACT OF DENYING is what is selfcontradictory.
If you doubt it, you find that you cannot doubt it
We want to ask why this is the case –why can nothing shake us in our belief?
Now… why is the denial of the cogito is selfcontradictory (if you doubt it you cannot
Take the idea my car is red
Denial is my car is not red
Is the denial here selfcontradictory?
NO! Being red is NOT part of the meaning of my car
Can think of car without thinking that it is red.
Take the claim “I think therefore I exist”
Denial – “I think but do not exist”
The colour red is not necessarily connected to the car – they need to give it a red paintjob
What about connection between thought and existence?
Descartes believes that once you think of yourself thinking, you must think of yourself
Thought and existence, as we have said before, are necessarily connected.
You would need to think of yourself as thinking, but deny that you exist.
What happens if we try to do this?
We want to think ourselves as thinking, but separate existence from this
AS soon as you do this, however, you can no longer think of yourself as thinking
Therefore, if you try to doubt the cogito, you find that you cannot doubt it. This is the
contradiction – it is the act of doubting.
To attempt to doubt the connection requires affirming in thought the first idea, while at
the same time, denying the 2 one. However, since the natures are inseparable, this is
impossible: once we deny the second idea, we find two cannot think of the first.
Therefore, if we begin to try to doubt these connections, we will find that we cannot
doubt them –either the second is thought while the first is thought, or the first cannot be
thought. TO think the first, therefore requires thinking of the 2 at the same time. CK42 REGULAE:
Talks about this necessary connection with the ideas of figure/extension,
motion/duration., and 7=4+3
If two concepts are necessarily connected they are inseparable from each other
If you think the first relatum (shape, something moving, 7) you have to think the second –
otherwise you can’t think it!
So a test we can do is trying to think of the first without thinking of the second.
If inseparable, you would think the first and have to think the second.
Can you think of a desk that doesn’t occupy space? How about motion that doesn’t take
place in time? A set of 7 that isn’t a set of 4 and 3?
If you deny set of 4/3 as equivalent to 7, you are no longer thinking of 7!
So with cogito trying to think of yourself as thinking, but deny existence
simultaneously. If you do so you can no longer think of yourself as existing.
What’s why we get: if the cogito is doubted, you cannot doubt it – they are inseparable
D wants to show that this applies to all CD connections –if you doubt them, you cannot
(We can put C/D ideas in the reductio above)
Here CK 52R D talks about how some CD truths God cannot deceive us about
Note that here mathematical equations are NOT in the list (axioms are)
Says that cogito is a clear and distinct truth that not even the hypothesis of
deceptive god can shake
Therefore, conceptually they all operate in the same way – denial is always self
contradictory… if you try to doubt, you cannot.
On the other hand;
We have the claim of D that ONLY the cogito when proven denial is selfcontradictory
prove its truth Motion connected to duration is selfcontradictory if denied, but this does NOT prove its
lets start with 3+2=5
When someone says this statement is true, what do they mean?
Objectives in the world will behave in accordance with this formula
Mat has a representative feature – it represents collections of things in reality
D maintains that we still have to establish that the mathematical equation represents
reality. I might think 7=4+3 but this doesn’t mean that it reflects reality!
Does reality reflect the way I’m thinking about it?
There is an idea that with mathematical concepts what you’re thinking is NOT identical
to what you are thinking about
Because math is representational; the fact that you can’t think that 7=4+3 does not prove
that it is indeed truth
Recall; in mathematics what you are thinking is different than what you are thinking
about – you are thinking about how objects behave in the world, what you are thinking is
how you are PI to think of these things, and if God is a deceiver he can make you think
one way and make the world another way.
He can make you believe in an equation that is in fact disconnected from reality that
exists in the world