Meditations on First Philosophy

Summary

Meditationes de prima philosophia, published in Paris in 1641, compresses Descartes's metaphysics into six meditations, each imagined as a day's reflection by a solitary thinker seated by the fire in a dressing gown. The book was issued with six sets of Objections from learned readers (Caterus, Mersenne's circle, Hobbes, Arnauld, Gassendi and others) and Descartes's Replies, which are longer than the Meditations themselves; a second edition (Amsterdam, 1642) added the Jesuit Bourdin's Seventh Objections. The first meditation clears the ground. Since the senses sometimes deceive, the meditator resolves to withhold assent from everything that can be doubted. He considers madmen who believe they are kings when they are paupers or that their heads are made of earthenware or their bodies of glass, and rejects the comparison, only to recall that in dreams he has believed himself dressed by the fire while lying undressed in bed. Even mathematics might be false if an all-powerful God, or an evil genius supremely powerful and cunning, deceives him. The second meditation finds a fixed point: however much he is deceived, he must exist in order to be deceived, so the proposition 'I am, I exist' is necessarily true whenever it is thought. What he is, so far, is only a thinking thing, one that doubts, understands, affirms, denies, wills, imagines and senses. A piece of beeswax, which keeps its identity through melting when its every sensory quality changes, shows that bodies too are known by the intellect rather than the senses. The third meditation argues from the idea of an infinite, perfect being in his finite mind to the existence of God as its only possible cause, and the fourth explains error as the result of a finite intellect combined with an unlimited will that assents beyond what it clearly perceives. The fifth meditation offers a second proof of God, that existence belongs to the essence of a supremely perfect being as necessarily as three angles equal to two right angles belong to a triangle, and argues that the certainty of geometry depends on knowing God. The sixth meditation restores the material world: because a non-deceiving God has given us a strong inclination to believe our ideas of bodies come from bodies, bodies exist, though they are only what geometry describes, extension in length, breadth and depth. Mind and body are really distinct substances, since each can be clearly conceived without the other. Yet the meditator is not lodged in his body like a pilot in a ship; hunger, thirst and pain show that mind and body form a kind of unity. The meditation ends with a physiology of error: pain felt in an amputated limb, the thirst of a patient with dropsy, and the transmission of motion along nerves to the brain show how a well-designed body can sometimes mislead, and the closing paragraph dismisses the hyperbolic doubt about dreaming, since waking experience coheres with memory as dreams do not.

Top Lessons

• Doubt used as a method, not a mood

  Descartes doubts systematically and temporarily, in order to find what cannot be doubted. The Meditations distinguish a disciplined procedure of suspending belief from the sceptic's lasting uncertainty.

• The self known as a thinking thing

  The second meditation identifies the self with its thinking before establishing that it has a body. That starting point has shaped centuries of debate over whether minds can be understood apart from brains.

• Not a pilot in a ship

  Even after arguing that mind and body are distinct substances, Descartes insists that sensations like hunger and pain show an intimate union. The sixth meditation is less dualist in feeling than its reputation suggests.

• When a healthy design misleads

  Descartes explains phantom limb pain and the thirst of dropsy as cases where a mechanism that usually serves survival produces false signals. The argument anticipates modern ideas of adaptive systems misfiring in disease.

Verified Quotes

Medical Lens

The Meditations are the classical statement of mind–body dualism, the position against which much of modern psychiatry, neurology and psychosomatic medicine has defined itself, often polemically (Damasio's Descartes' Error). Close reading shows a more embodied Descartes: the sixth meditation insists on the felt union of mind and body and gives mechanistic explanations of sensation via nerves and brain. The first meditation's madmen, who believe their heads are earthenware or their bodies made of glass, refer to the 'glass delusion' recorded by early modern physicians, a historically specific form of delusion. Meditation VI discusses phantom limb pain reported by amputees and the pathological thirst of dropsy (oedema) as examples of nature's signals misfiring. The dream argument makes dreaming a central problem for epistemology. Retrospective readings of Descartes's own 1619 dreams as evidence of a mental crisis are speculative.

• Meditation I

  The meditator considers madmen whose brains are disturbed by black bile, who believe they are kings, or that their heads are earthenware or their bodies glass.

• Meditation I

  The dream argument: no certain marks distinguish waking from sleeping.

• Meditation II

  Identification of the self as a thinking thing whose existence is certain independent of any knowledge of the body.

• Meditation VI

  Argument for the real distinction of mind and body, followed by the claim that the mind is not in the body as a pilot in a ship, as hunger, thirst and pain show.

• Meditation VI

  Phantom pain felt by those whose arm or leg has been amputated, used to show that the senses can mislead about the location of pain.

• Meditation VI

  Nerves compared to a cord whose pull at any point produces the same motion in the brain; the dropsical patient's thirst as a natural signal that harms the sick body.