Meditation 5 — Of the Essence of Material Things; And, Again, Of God
Before returning to the world, Descartes takes stock of what he can clearly and distinctly conceive — and arrives at a second proof of God's existence that is even shorter and more vertiginous than the first.
Summary
Descartes turns to material things before demonstrating that they exist — he wants first to examine his clear and distinct ideas of them, to see what he can know about them without yet committing to their existence. He finds he has a clear and distinct idea of quantity — extension in three dimensions — and that within this idea he can discover all kinds of properties of shapes, sizes, and spatial relations that seem to have been there all along, not invented by him. When he discovers that the angles of a triangle equal two right angles, he is not inventing this — it was already there in the nature of the triangle, waiting to be found. Mathematical truths are true and immutable, even if no triangle has ever existed outside the mind.
He then asks: do I find the idea of an actually existing God anywhere in my mind in the same way? Yes: I have the idea of a supremely perfect being, and existence belongs to that being no less necessarily than having three angles belongs to a triangle. A triangle whose angles did not sum to two right angles would not be a triangle at all. A supremely perfect being that lacked existence would not be supremely perfect at all. Therefore the idea of a supremely perfect being implies existence — God must exist.
He anticipates the obvious objection: from the fact that I cannot think of a mountain without a valley, it does not follow that any mountain exists. Why should God be different? Descartes's reply: the mountain and the valley case proves only that the two are inseparable from each other in my conception — not that either exists. But in God's case the inseparability is between the concept of maximal perfection and existence itself. I am not free to conceive of God as non-existing any more than I am free to conceive of a triangle whose angles do not sum to two right angles. Existence is packed into the concept of perfect being at the most fundamental level. The Fifth Meditation ends with the observation that knowledge of God is the firmest and most certain of all — because God's existence is contained in God's essence, and I cannot separate the two even in thought.
- Letter of DedicationDescartes addresses the theologians of the Sorbonne, explaining that he intends to prove by natural reason that God exists and...
- Preface to the ReaderDescartes addresses the reader directly and answers in advance the two main objections raised against his 1637 sketch of the...
- SynopsisA six-paragraph map of the entire argument. Descartes describes what each meditation establishes — and notes, with characteristic...
- Meditation 1The great demolition. Descartes takes apart his beliefs layer by layer — the senses, then dreaming, then the evil deceiver — until...
- Meditation 2The cogito and the wax example. In the wreckage of total doubt, Descartes finds that the thinking, doubting self cannot be doubted...
- Meditation 3The trademark argument for God's existence. Descartes examines the idea of God in his mind — infinite, all-powerful, all-knowing...
- Meditation 4The source of error: not a defect in the intellect, but the will extending beyond what the intellect clearly perceives. Descartes...
- Meditation 5Two arguments in one meditation: mathematical objects have true natures independent of whether they exist in the world; and God...
- Meditation 6Bodies exist; mind and body are really distinct substances; and yet they are also intimately united — felt together in every...