Lecture Notes

Lecture Notes: September 30

Note that page numbers herein refer to the Adam and Tannery page numbers, located in the margins of the text.

Meditation III

If we are going to rebuild our knowledge, then we need a way to know that we know something, a test or...

Criterion for Knowledge

p 34-5: What is the goal of the meditations?
skepticism -> certainty
Recall the general doubts about relying on the senses as source of knowledge

If we are to gain certainty, we have also to know that we know
p 35: Descartes' criteria for knowledge: clarity and distinctness
What could these mean?
A metaphor, from Descartes' Principles of Philosophy, I.45:

"Something is clear when it is present and apparent to an attentive mind, in the same way as we assert that we see objects clearly when, being present to the regarding eye, they operate upon it with sufficient strength"

Perhaps the specific formulation isn't important, but what's important is that there be some distinguishing mark
Without such a mark, all searching for certainty is useless.
Later (p 38) Descartes refers to the light of nature as the securer of truth.
This light of nature is distinguished from instinct, or being taught by nature

According to MII, if there were objects, how would we know about them (e.g. the wax)?

By intellect, or pure reason, alone.

Perhaps "alone" is too strong, but recall that any information from the senses is doubtable.

So it is only the knowledge gained beyond that provided by the senses which counts as knowledge.
What properties may thus exist clearly and distinctly in the objects?
Extension, plus the ability to appear in different guises (they are "flexible and mutable", p 31)
What then can we say of the sensory properties of objects?

Resemblance Hypothesis

p 35: Resemblance Hypothesis, that our ideas of objects resemble those objects, is rejected
Argument for the resemblance hypothesis:

1) I have ideas about objects involuntarily
2) Involuntary ideas come from outside of me
3) An object sends to me its own likeness
So, my idea resembles its cause, i.e. its object

Locke will defend this thesis; so will Berkeley, in an odd way

Descartes rejects the resemblance hypothesis
Agrees with premise 1, although says that those ideas can lead one astray
Against Premise 2): I may have a heretofore unnoticed ability to create these images
Against Premise 3): the sun (p39) appears small to my senses, but my reasoning tells my it's large

Also, the moral of the wax story is that sensory information is not knowledge

And the stars of MVI (p82-3), which appear the size of a flame, but are much larger

We've discovered a reason for making sensory errors: reliance on the RH
This is independent of the doubts

We would have this problem even if the exaggerated doubts weren't there
So, let's look at our ideas, and see if we can delete the ones which depended on RH
Maybe that will leave us in better shape to conquer the doubts

Cataloguing Ideas

The contents of the mind (p 37)

1) simple ideas (pictures)
2) emotions, or affects, (idea + feeling)
3) volitions (idea + willing)
4) judgments (2+2=4; that I want or feel x or y; 'snow is white'; that an idea resembles an object)

[Note: in class I combined the above second and third categories into one category]

Thoughts of types 1,2, and 3 can't be wrong

"Ideas can not be false"

Only thoughts of type 4 can be false
These are sometimes known as 'propositions'

Where do ideas they come from?

p 38

1) innate (judgments based on these are a priori)
Distinguish these from instinctive abilities
2) acquired (judgments based on these are a posteriori or empirical)
3) produced by me (also a posteriori)

Note that only those of classes 2 and 3 are subject to RH
The innate ideas are clean of RH infection
We can see why the "light of nature" yields these innate ideas
They can be C&D because they aren't affected by RH
Those of class 3 we never thought as yielding truth, anyway

Summary of the First Part of MIII

Does the criterion help?

The Problem of Cartesian Circularity:
Is the criterion circular? (Is C&D itself clear and distinct?)

Don't we at least have math?

p 36: this is still doubtable, due to the possibility of the deceiver
We need God as a way to defeat the deceiver, still, despite rejecting RH
The proofs of God Descartes uses are based on our ideas (as that's all we have that is certain)
We established only the cogito

Descartes and Anselm (1033-1109) on God

Proof of God's existence in MIII is difficult and medieval
See Aquinas for different kinds (and Berkeley, too)
Descartes has another proof, in MV, (pp 64-8)

Define 'God': necessarily existent being
also, as all perfections: p 47 and p 67

and as creator and preserver: pp 48-9
for Anselm's purposes: that than which no greater can be conceived

These are definitions of a term, a word

There's no presupposition that the object exists

Since these are different definitions, there could be conflict

Anselm's Ontological Argument for God's existence (See handout, Chapter II):

1) I can think of 'God'
2) If 'God' were just an idea, then I could conceive of something greater than it (i.e. an existing God)
3) But 'God' is that than which nothing greater can be conceived
4) So 'God' can't be just an idea
:. God exists

Anselm further argues that one can't even conceive of god not to exist, in Chapter III

That's not in Descartes

Descartes' version (p 65-66)
Simpler, as it doesn't depend on our ability to have the conception
Existence is part of the essence of God, just as 180 degrees is part of the essence of triangle
The essence of an object is all the properties of an object, the necessary and sufficient conditions for being that object
Something that has all these properties is one
Something that lacks any of these properties is not one
Chair's essence: for sitting, has a back (probably), furniture, concrete, durable material
The essence of human person: body and mind
The essence of God: All perfections, including existence!

Just as a mountain is essentially connected to a valley, existence is essentially connected to God's essence

The concept of a perfect being contains the concept of existence, and thus must exist!

Where does this idea of God come from?
MIII (p51) as a mark on the work
i.e. It's innate

Problems with the concept of a perfect being:
1) evil (and omni-benevolence)
2) error (and omnipotence)
3) free will (and omniscience)

Objection from Caterus, Dutch philosopher, in Objections 1
The concept of a necessarily existing lion has existence as part of its essence, but it entails no actual lions.

We have not discussed the following, but I include it here, FYI:

Another problem with omni-benevolence, from Leibniz
1) God is omnipotent so he can create the best possible world
2) God is omni-benevolent, so he wants to create the best possible world
3) The world exists
:. This is the best of all possible worlds
(and all of the evil necessary!)