Meditations on First Philosophy

Meditations on First Philosophy (subtitled In which the existence of God and the real distinction of mind and body, are demonstrated), written by René Descartes (1596 - 1650) and first published in 1641, expands upon Descartes' philosophical system, which he first introduced in his Discourse on Method (1637).

The book is made up of 6 meditations, during which Descartes discards all belief that is not absolutely certain, then tries to establish what can be known for sure.

Meditation I: On What Can Be Called into Doubt

Meditation I is written in first person and in the dialectic style. It proceeds through three stages in "tearing down" opinion with one common principle throughout. The principle is that one should refrain from asserting anything that is uncertain just as if it was false. However, he recognized that the mind has a habit of believing what it perceives and, thus, the will must deliberately suppose that all prior beliefs are false. In order to support this, he discusses three stages: senses, dreams, and the evil demon hypothesis.

Although each of these can falsify our perceptions, Descartes asserts that they do not have the power to falsify what we "seem" to perceive. The powers to think and exist are also deemed untouchable.

Meditation II: On the Nature of the Human Mind, Which Is Better Known Than the Body

In Meditation II, Descartes lays out a pattern of thought sometimes called representational theory in response to the doubts forwarded in Meditation I. He identifies five steps in this theory:

We only have access to the world of our ideas; things in the world are only accessed indirectly.
These ideas are understood to include all of the contents of the mind, including perceptions, images, memories, concepts, beliefs, intentions, decisions, etc.
The ideas represent things that are separate from themselves.
These represented things are many times "external" to the mind.
It is possible for these ideas to constitute either accurate or false representations.

Descartes argues that this representational theory disconnects the world from the mind, leading to the need for some sort of bridge to span the separation and provide good reasons to believe that the ideas accurately represent the outside world. The first plank he uses in constructing this bridge can be found in the following excerpt:

I have convinced myself that there is nothing in the world - no sky, no earth, no minds, no bodies. Doesn't it follow that I don't exist? No, surely I must exist if it's me who is convinced of something. But there is a deceiver, supremely powerful and cunning whose aim is to see that I am always deceived. But surely I exist, if I am deceived. Let him deceive me all he can, he will never make it the case that I am nothing while I think that I am something. Thus having fully weighed every consideration, I must finally conclude that the statement "I am, I exist" must be true whenever I state it or mentally consider it.

Descartes, Meditation II: On the Nature of the Human Mind, Which Is Better Known Than the Body

In other words, one's consciousness implies one's existence. In one of Descartes' replies to objections to the book, he summed this up in the now-famous phrase, I think, therefore I am.

Once he has secured his existence, however, Descartes seeks to find out what "I" is. He rejects the typical method which looks for a definition because the words used in the definition would then need to be defined. He seeks simple terms that do not need to be defined in this way, but whose meaning can just be "seen." From these self-evident truths, complex terms can be built up.

The first of these self-evident truths is Descartes' proof of existence turned on its head:

But what then am I? A thinking thing. And what is that? Something that doubts, understands, affirms, denies, wills, refuses, and also sense and has mental images.

Descartes, Meditation II: On the Nature of the Human Mind, Which Is Better Known Than the Body

To define himself further, Descartes turns to the example of wax. He determines that wax isn't wax because of its color, texture or shape, as all of these things can change and the substance still be wax. Therefore, he distinguishes between ordinary perception and judgement. The reality of the wax is "grasped, not by the senses or the power of having mental images, but by the understanding alone." When one understands the mathematical principles of the substance, such as it's expansion under heat, figure and motion, the knowledge of the wax can be clear and distinct.

If a substance such as wax can be known in this fashion, then the same must be of ourselves. The self, then, is not determined by what we sense of ourselves - these hands, this head, these eyes - but by simply the things one thinks. Thus, one "can't rasp anything more easily or plainly than [their] mind."

Meditation III: On God's Existence

Building upon the foundation that "I exist," Descartes seeks to prove that "I am not alone" in Meditation III. Along the way, he solves the skeptical problem of the criterion with an argument as follows:

I exist as a thinking thing.
How can I be certain?
Because I grasp it so clearly and distinctly that it could not possibly be false.
Whatever is grasped with like clarity and distinctness is also true.

Next, before proceeding with his arguments, Descartes organizes the contents of the mind into ideas and ideas in action. The former have three possible sources; they are either innate, acquired from outside the self or produced by the self. The latter are made up of judgments, volitions and emotions. He also distinguishes between formal reality and subjective reality; the former being what is real (e.g., an actual giraffe or an actual thought of a giraffe) and the latter representing ideas that are self-produces (e.g., the tooth fairy or unicorns).

Using the "clarity and distinctness" criterion, Descartes then seeks to prove he is not alone by proving that God exists. He chooses this method because without a knowledge of whether God exists or if he is a deceiver, there is no way to discuss the all-powerful deceiver challenge of reality. In order to do this, he first establishes a causal principle: There must be at least as much reality in the cause as there is in the effect. For example, if a thought of an elephant is caused by a picture of an elephant, the picture must have as much reality as the thought. If it were not so, it could not have produced it.

Using this causal principle, Descartes lays out two ontological arguments in Meditation III for the existence of God. The first begins with the fact that each of us has an idea of God and the second begins with the fact that it is true that the self exists.

Argument 1

I have an idea of God (an infinitely perfect substance).
That idea must have a cause.
Nothing comes from nothing.
The cause must have at least as much formal reality as the idea.
I am not infinitely perfect.
I could not be the cause of the idea.
There must be a cause that is infinitely perfect.
God exists.

Argument 2

I exist.
My existence must have a cause.
The cause must be either:

a) myself

b) my always having existed

c) my parents

d) something less perfect than God

e) God

Not a. If I would have created myself, I would have made myself perfect.
Not b. Continued existence does not follow from present existence.
Not c. This leads to an infinite regress.
Not d. This idea cannot account for the fact that the idea is of something supreme.
e. God exists.

From these arguments, Descartes feels he has proved he is not alone in the universe as an infinitely intelligent and powerful and perfect substance exists, also. Not only that, but that this God cannot be a deceiver:

The whole argument comes down to this: I know that I could not exist with my present nature - that is, I could not exist with the idea of God in me - unless there were really a God. This must be the very God whose idea is in me, the thing having all of the perfections that I can't fully comprehend but can somehow reach with thought, who clearly cannot have any defects. From this it's obvious He can't deceive - for, as the natural light reveals, fraud and deception arise from defect.

Descartes, Meditation III: On God's Existence

Meditation IV: On Truth and Falsity

Descartes argues that the truthfulness of certain claims can be verified by comparing it, with no room for doubt, against the falsity.

Meditation V: On the Essence of Material Objects and More on God's Existence

to be written

Meditation VI: On the Existence of Material Objects and the Real Distinction of Mind from Body