French Catholic idealist philosopher; b. Fontainebleau, May 27, 1832; d. there, Jan. 18, 1918. After graduation from the École Normale Supérieure, he studied philosophy privately under Félix Ravaisson (1813–1900). From 1864 to 1875 he taught philosophy at the École Normale Supérieure, but resigned because of a secret fear of disturbing his students' faith. He served in the university administration from 1875 to 1910, but his influence on young professors of philosophy remained great, and perdures through the 20th century.
Lachelier's idealism, Platonist and Leibnizian rather than Kantian, is based on the incompatibility of realism with absolute scientific determinism. The latter demands absolute homogeneity of all parts of matter, and therefore excludes any qualitative diversity whereby individual things can have distinct existence. Hence absolute scientific determinism implies that its object is purely mental. Mechanism thus proceeds from mind, but from impersonal mind that cannot be other than the object it thinks. Mechanical necessity is therefore a purely intelligible object of mathematical physics, from which all sensible qualities and distinct bodies, whether living or nonliving, are absent.
Impersonal mind does not stop at this level of abstract thought. Rather, by a pure act of instinct, it organizes distinct bodies harmoniously into a cosmos. By producing a world of real bodily units, impersonal mind itself becomes real through its real object.
Yet impersonal mind cannot be other than its object, which is still blind instinct. To become intellectual thought, impersonal mind reflects on itself and sees that it is the act whereby all things have being and truth. This creative act is man's intellectual judgment in which he judges the world of instinct to be true being. The human intellect, however, can only apply its judgment to instinctive finality that antedates it and to which it must passively conform. Since passive conformity is contrary to the nature of mind, the possibility remains that Pure Thought (God) may exist independently of human sense consciousness. God's existence is an unverifiable possibility, however, because experience is sufficiently explained without it.
In criticism, one should note that Lachelier's idealism was based on an absolute mechanical determinism later rejected by the physical sciences. His argument against natural units resembles the common scholastic argument that natural units are composed of primary matter and substantial form. To the extent that he acknowledged the human mind's passivity to the instinctive cosmos, Lachelier was a realist.
See Also: idealism
Bibliography: Oeuvres, 2 v. (Paris 1933). The Philosophy of Jules Lachelier, tr. e. g. ballard (The Hague 1960). l. millet, Le Symbolisme dans la philosophie de Lachelier (Paris 1959), excellent bibliog. e. g. ballard, "Jules Lachelier's Idealism," Review of Metaphysics, 8 (1954–55) 685–705. r. a. powell, Truth or Absolute Nothing: A Critique of the Idealist Philosophy of Jules Lachelier (River Forest, Ill. 1958). a. g. sertillanges, Le Christianisme et les philosophies, 2 v. (Paris 1939–41). v. mathieu, Enciclopedia filosofica, 4 v. (Venics–Rome 1957) 2:1766–68.
[r. a. powell]