hour after its removal from the body; the parts of cut-up polyps grow into perfect animals).  All ideas come from without, from the senses; without sense-impressions no ideas, without education, few ideas, the mind of a man grown up in isolation remains entirely undeveloped; and since the soul is entirely dependent on the bodily organs, along with which it originates, grows, and declines, it is subject to mortality.  Not only animals, as Descartes has shown, but men, who differ from the brutes only in degree, are mere machines; by the soul we mean that part of the body which thinks, and the brain has fine muscles for thinking as the leg its coarse ones for walking.

[Footnote 1:  La Mettrie was born at St. Malo, and educated in Paris, and in Leyden under Boerhave; he died in Berlin, whither Frederick the Great had called him after he had been driven out of his native land and from Holland.  On La Mettrie cf.  Lange, History of Materialism, vol. ii. pp. 49-91; and DuBois-Reymond’s Address, 1875.]

If man is nothing but body, there is no other pleasure than that of the body.  There is a difference, however, between sensuous pleasure, which is intense and brief, and intellectual pleasure, which is calm and lasting.  The educated man will prefer the latter, and find in it a higher and more noble happiness; but nature has been just enough to grant the common multitude, in the coarser pleasures, a more easily attainable happiness.  Enjoy the moment, till the farce of life is ended!  Virtue exists only in society, which restrains from evil by its laws, and incites to good by rousing the love of honor.  The good man, who subordinates his own welfare to that of society, acts under the same necessity as the evil-doer; hence repentance and pangs of conscience, which increase the amount of pain in the world, but are incapable of effecting amendment, are useless and reprehensible:  the criminal is an ill man, and must not be more harshly punished than the safety of society requires.  Materialism humanizes and exercises a tranquilizing influence on the mind, as the religious view of the world, with its incitement to hatred, disturbs it; materialism frees us from the sense of guilt and responsibility, and from the fear of future suffering.  A state composed of atheists, is not only possible, as Bayle argued, but it would be the happiest of all states.

Among the editors of the Encyclopedia, the mathematician D’Alembert (Elements of Philosophy, 1758) remained loyal to skeptical views.  Neither matter nor spirit is in its essence knowable; the world is probably quite different from our sensuous conception of it.  As Diderot (1713-84), and the Encyclopedia with him, advanced from skepticism to materialism, D’Alembert retired from the editorial board (1757), after Rousseau, also, had separated himself from the Encyclopedists.  Diderot[1] was the leading spirit in the second half of the eighteenth century, as Voltaire