La Mettrie and Helvetius resemble each other in ethical doctrine. Both make pleasure and pain the ruling motives of man's conduct. They claim that all the emotions are merely modifications of corporeal pleasure and pain, and that therefore the only principle of action in man is the desire for pleasure and the fear of pain. [52] b. The Likeness to La Mettrie of the French Materialist, Baron Paul Heinrich Dietrich von Holbach (1723-1789). As Condillac and Helvetius emphasize the sensationalism taught by La Mettrie, so Holbach's book is a reiteration and elaboration of the materialism set forth in La Mettrie's works. The teaching of Holbach is so like that of La Mettrie, that the similarity can hardly be a coincidence. La Mettrie regards experience as the only teacher. Holbach dwells on this same idea, and insists that experience is our only source of knowledge in all matters. [53] Holbach likewise teaches that man is a purely material being. He disbelieves in any spiritual reality whatsoever, and makes matter the only substance in the world. He lays stress, also, on one thought which is a natural consequence of La Mettrie's teaching. La Mettrie has limited the action of the will and has insisted that the will is dependent on bodily conditions. Holbach goes further and declares repeatedly that all freedom is a delusion, and that man is controlled in every action by rigid necessity. [54] This teaching seems to be the natural outcome of the belief that man is a machine. Holbach's atheistic theology is more extreme than his predecessor's, for La Mettrie admits that God may exist, while Holbach vigorously opposes the possibility. Moreover Holbach holds the opinion, barely suggested by La Mettrie, that an atheistic doctrine would ameliorate the condition of mankind. [55] He insists that the idea of God has hindered the progress of reason and interfered with natural law. Holbach is indeed the only one of the philosophers here discussed, who frankly adopts a fatalistic and atheistic doctrine of the universe. In these respects, his teaching is the culmination of French materialism. OUTLINE OF LA METTRIE'S METAPHYSICAL DOCTRINE. PAGES [56] I. Insistence on the Empirical Standpoint 16f.; 88f.; 72, 142 II. Arguments in Favor of Materialism: