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Philosophical Works · Chapter

CXCVI explained

This chapter argues that the soul perceives only insofar as it is in the brain, not in each member of the body.

What happens

This chapter argues that the soul perceives only insofar as it is in the brain, not in each member of the body. Three proofs are offered: maladies affecting only the brain disrupt sensation; obstruction of nerves anywhere between brain and member abolishes sensation in that member; and phantom limb pain demonstrates that sensations like pain are felt in the brain, not in the limb itself.

Themes in this chapter

  • Mind-Body Dualism

    The chapter reinforces the distinction between the immaterial soul and the material body by locating perception solely in the brain.

  • Reason and Method

    Descartes uses empirical observations and logical proofs to establish a physiological basis for perception.

Characters to notice

  • Narrator

    Presents the argument and the experimental example of the girl with the amputated arm.

Key passages

  • the soul does not perceive in so far as it is in each member of the body, but only in so far as it is in the brain

    The mind perceives not through each body part but solely through the brain.

    Central thesis of the chapter.

  • A girl suffering from a bad ulcer in the hand... complained of feeling various pains, sometimes in one finger of the hand that was cut off, and sometimes in another.

    A girl whose arm was amputated without her knowledge still felt pain in her missing fingers.

    Empirical evidence that pain is perceived in the brain, not the limb.