The Passions of the Soul

The central claim is that the passions are perceptions caused by the animal spirits and directed toward the soul's interaction with the body, and that virtue consists in the rational regulation of these movements rather than their suppression. Descartes rejects the Stoic view that the passions should be extirpated as diseases of the soul. He also rejects the Scholastic account of the passions as movements of the sensitive appetite, substituting a mechanistic physiology in which the pineal gland mediates between body and soul. The work's ethical ideal is generosity (générosité)—a self-esteem grounded in the proper use of free will—which Descartes presents as the key to mastering the passions and attaining tranquillity.

The pineal gland is the point of contact between body and soul. Descartes argues that the soul is united to the whole body but exercises its function more particularly in the pineal gland, where the animal spirits converge and where the soul can redirect them by an act of will. The passions arise when the animal spirits, agitated by external objects or internal dispositions, move the pineal gland in a way that produces a perception in the soul. This physiological account allows Descartes to explain the involuntary character of the passions while preserving the will's capacity to regulate them. The pineal gland's role has been widely criticized, both by contemporaries and by modern commentators, as an implausible solution to the mind-body problem, but it is essential to Descartes's account of the union.

Descartes identifies six primitive passions: wonder, love, hatred, desire, joy, and sadness. All other passions are species or combinations of these. Wonder is the first passion, a sudden surprise caused by an object's novelty; love and hatred concern the soul's evaluation of objects as good or bad for it; desire is the movement toward what is loved or away from what is hated; joy and sadness are the soul's pleasures or pains arising from its evaluations. By reducing the passions to a small number of primitives, Descartes aims to provide a systematic taxonomy that can be explained physiologically and ethically. The reduction also allows him to argue that the passions are all good in themselves—it is only their misuse or excess that is harmful.

The Passions is the culmination of Descartes's philosophical project, drawing on the physiology of the Treatise on Man, the metaphysics of the Meditations, and the moral reflections sketched in the Discourse and the correspondence with Princess Elisabeth. It fills a gap that had long been noted in Descartes's system: the absence of a systematic moral philosophy. The work also develops the account of the mind-body union that the Meditations had largely bracketed, showing how the soul can be affected by the body and how it can regulate the body's movements. In this sense, the Passions is the most practical of Descartes's works, concerned with how to live rather than merely how to know.

The Passions was first published in French in 1649 by Elsevier in Amsterdam, with a Paris edition by Henry Le Gras appearing shortly after . The French text is the original; a Latin translation by Henry Desmarets appeared in 1650. The first English translation, by an anonymous translator, was published in London in 1650 as The Passions of the Soule . A modern English edition by Stephen Voss, based on the French text, appeared in 1989; it was reissued with a revised translation in 1990 . The Cambridge edition includes the Passions in its volume on the philosophical writings, translated by Robert Stoothoff. Readers should note that the work's French original is the authoritative text, and that translations differ in their handling of key terms like générosité.

A frequent misreading treats Descartes as a rationalist who denigrates emotion and seeks to subordinate all feeling to reason. In fact, the Passions defends the passions as good in themselves: they are natural and necessary movements of the soul, and Descartes explicitly rejects the Stoic ideal of extirpating them. What the will can do is regulate them—not by suppressing them but by redirecting the animal spirits through reason and by cultivating the habit of virtue. The master passion, generosity, is itself an emotion: a kind of self-esteem grounded in the right use of free will. Descartes's ethics is therefore an ethics of emotional regulation, not of emotional suppression, and its goal is tranquillity rather than apathy.