Lecture 18 Notes

Meditation 2

Plan of the Lecture

I. A Brief Review
II. Some Doubts About Doubt
III. Meditation 2

I. A Brief Review

A. Rival Paradigms of Knowledge

Where Aquinas took theological and philosophical knowledge as the paradigm of knowledge, Descartes thinks geomterical knowledge is paradigmatic:

Its foundations are most evidently secure to us.
It displays an internal structure that guarantees certainty.

B. Descartes' Program

Descartes tries to determine which of his beliefs are certain, that is, which can be made conform to the geometric model.
The task of philosophy is to determine which are as certain as axioms, or which follow from such beliefs by self-evident steps.

C. Sources of Doubt in Meditation I

Sensory Error
Dream Hypothesis
Deception by God
Evil Genius

II. Some Doubts About Doubt

A. MEDITATION I begins modern philosophy:

For Aquinas, how we know requires an explanation, i.e. by reference to the forms, etc. That we know is unproblemmatic. Descartes introduces question of whether we know. This question has captivated modern philosophy since.
There is something captivating about the question. Surely what Descartes suggests seems intriguing; it is the stuff of science fiction. And insofar as we can write science fiction about it, it must be possible. Philosophy’s job is to investigate all possibilities.

B. Two Problems About the Hypothesis of Meditation 1

The argument of Meditation 1 makes essential use of the notions of 'doubt' and 'certainty': we doubt whatever is not certain. These notions are meaningful in ordinary circumstances: if we have doubt whether crime has been committed, a person isn't guilty. Following this example, in order to make meaningful use of the notion of doubt, we must have standards of evidence about how doubt is dispelled. Those standards themselves depend upon paradigms of certainty. Therefore, some philosophers think it is incoherent to doubt everything.
We might also think that standards of evidence depend upon the existence of a community that accepts and uses standards. Descartes' doubt depends on a community of readers of his book. As a result, the solitary doubt of Meditation 1 is incoherent.

III. Meditation 2: Knowledge of Mind, Knowledge of Matter

A. Challenge to Descartes

The 'I' of the cogito is mysterious and elusive.

It is mysterious because, though we know that it thinks, doubts, etc., we don’t know how it does these, what holds powers together.
It is elusive because it is hard or impossible to perceive the self.

Therefore, we don’t seem to know it very well. There must be other, better foundations. How can the cogito, Descartes’ knowledge that he is a thinking thing, be the foundation of all knowledge? Our knowledge of bodies seems so vivid and pungent, so clear and distinct. Don’t we know bodies through sensation better than we know minds through introspection?

B. Descartes's Reply

What makes the perception of bodies seem so clear are their appearance, smell, taste, touch. Consider, for example, a solid piece of wax. So if what we know most vividly is what we know most truly, then it must be that we know bodies through sensations. But we don’t know a body through these, since a body can remain the same thing, through these changes, e.g., wax. Therefore, we cannot know bodies through the senses
What we can know about wax is that it has the property of extension (takes up space) and it remains the same through melting. These things we know by intellectual inspection of wax. During inspection, mind is perceived and known more clearly than the wax.

C. Problems With Descartes's Reply

Mind is more clearly known in intellectual activity than the object of that activity, for example, wax. Two points about this claim:

It is not obviously true: consider being absorbed by music.
It sets up a claim that is very important for Descartes: we know best what we know clearly and distinctly

Next Time: we will see how this argument functions in Descartes’s argument for the existence of God.

Citation: Weithman, P. (2006, September 19). Lecture 18 Notes. Retrieved November 23, 2009, from Notre Dame OpenCourseWare Web site: http://ocw.nd.edu/philosophy/introduction-to-philosophy/lectures/lecture-18-notes.