He belonged to a noble family of Scottish descent, tracing its origin to Walter Stutt, who in 1420 accompanied the earls of Buchan and Douglas to the court of France, and whose family afterwards rose to be counts of Tracy. He was educated at home and at the university of Strassburg, where he was chiefly noted for his athletic skill. He went into the army, and when the Revolution broke took an active part in the provincial assembly of Bourbonnais. He was elected a deputy of the nobility to the states-general, where he sat alongside of his friend La Fayette. In the spring of 1792 he received the rank of maréchal de camp in command of the cavalry in the army of the north; but the influence of the extremists becoming predominant he took indefinite leave of absence, and settled at Auteuil, where, with Condorcet and Cabanis, he devoted himself to scientific studies.
Under the Reign of Terror he was arrested and imprisoned for nearly a year, during which he studied Condillac and Locke, and abandoned the natural sciences for philosophy. On the motion of Cabanis he was named associate of the Institute in the class of the moral and political sciences. He soon began to attract attention by the memoires which he read before his colleagues--papers which formed the first draft of his comprehensive work on ideology. The society of "ideologists" at Auteuil embraced, besides Cabanis and Tracy, Constantin François de Chasseboeuf, Comte de Volney and Dominique Joseph Garat (1749-1833), professor in the National Institute.
Under the empire he was a member of the senate, but took little part in its deliberations. Under the Restoration he became a peer of France, but protested against the reactionary split of the government, and remained in opposition. In 1808 he was elected a member of the Académie française in place of Cabanis, and in 1832 he was also named a member of the Academy of Moral Sciences on its reorganization. He appeared, however, only once at its conferences, owing to his age and to disappointment at the comparative failure of his work. He died at Paris on the 9th of March 1836.
Destutt de Tracy was the last eminent representative of the sensualistic school which Condillac founded in France upon a one-sided interpretation of Locke. He pushed the sensualistic principles of Condillac to their last consequences, being in full agreement with the materialistic views of Cabanis, though the attention of the latter was devoted more to the physiological, that of Tracy to the psychological or "ideological" side of man. His ideology, he frankly stated, formed "a part of zoology," or, as we should say, of biology. To think is to feel. The four faculties into which he divides the conscious life--perception, memory, judgment, will--are all varieties of sensation. Perception is sensation caused by a present affection of the external extremities of the nerves; memory is sensation caused, in the absence of present excitation, by dispositions of the nerves which are the result of past experiences; judgment is the perception of relations between sensations, and is itself a species of sensation, because if we are aware of the sensations we must be aware also of the relations between them; will he identifies with the feeling of desire, and therefore includes it as a variety of sensation. It is easy to see that such conclusions ignore important distinctions, and are, indeed, to a large extent an abuse of language. As a psychologist de Tracy deserves credit for his distinction between active and passive touch, which developed into the theory of the muscular sense. His account of the notion of external existence, as derived, not from pure sensation, but from the experience of action on the one hand and resistance on the other, may be compared with the account of Bain and later psychologists.
His chief works are Elements d'ideologie (1817-1818; 2nd ed., 1824-1825), in which he presented the complete statement of his earlier monographs; Commentaire sur I'esprit des lois de Montesquieu (1806; 5th ed., 1828; Eng. trans., President Jefferson, 1811); Essai sur le genie, et les ouvrages de Montesquieu (1808). See histories of philosophy, especially F Picavet, Les Ideologues chs. v. and vi. (Paris, 1891), and La Philosophie de Biran (Academie des sci. fnor. et pol., 1889); GH Lewes, Hist, of Phil.