body, Priestley believed that man would be restored to conscious existence when that event occurred. His principal works bearing on this subject are : " Examination of Reid, Beattie, and Oswald,'* " Doctrine of Philosophical Necessity Explained," " Disquisitions relating to Matter and Spirit," and " Hartley's Theory of the Human Mind, witli Essays relating to the subject of it."
Hume is regarded as their master by the most advanced phys- icists of the modern scientific school, so far as their general priuv-^i- ples and method of philosophizing ai'e concerned. He was neither a Materialist nor an Idealist, but rather a Nihilist, as his great object was to show that no certainty could be attained in any department of knowledge. He affirmed nothing and denied everything. Such knowledge as we have comes from sensation, therefore, he main- tained that as we have no sensation of efficiency, we can have no idea of it, and no evidence of its reality. A cause is not that which produces an effect, but simply that which uniformly precedes it. Consequently, anything can be the cause of anything. Again, as we have no perception by the senses of substance, there can be no such thing. This applies to mind as well as matter. Nothing exists to us but our thoughts and feelings. We are " nothing but a bundle or collection of different perceptions, which succeed each other with an inconceivable rapidity, and are in perpetual flux and movement."
C. Materialism in France during the Eighteenth Century.
The sensational philosophy, as it is called, found a much more congenial soil in France than in England. Locke's " Essay " was translated into the language of that country and made the subject of comments and lectures. His leading principles were adopted without the limitations and qualifications with which he had pre- sented them, and conclusions di'awn from them which Locke would have been the first to repudiate.
Condillac, one of the first and most influential of the disciples of Locke, in his first v/ork, ' Essai sur I'Origine des Connaissances Hu- maiues," differed comparatively little from the English pliilosopher. But in his ." Traitd des Sensations," he virtually discarded " reflec- tion " as a source of our ideas, and regarded all thoughts, feelings, and volitions as " transformed sensations." " While he answered the question concerning the relation between the soul and body, by assuming their identity, he took theistic ground in accounting for the origin of the world. This middle gi'ound was occupied also, at least ostensibly, by Diderot and D'Alembert in the French
254 PART I. — THEOLOGY. [Ch. m. ~ A^ti-Theism.
" Encjclopedie," who, notwithstanding their sensational theory as to the source of onr knowledge, and their making happiness the ground of morals and end of life, not onlj maintained theistic principles, but insisted on the necessity of a divine revelation. This, however, was probably more a matter of prudence than of conviction." ^
These, however, were only the first steps. The extreme of materialistic atheism was soon reached and avowed. La Mettrie published his " L'Histoire Naturelle de I'Ame " in 1745, his " L'Homme Machine," the same year, and his " L'Homme Plante " in 1749. Helvetius published his work " De I'Esprit " in 1758. His book entitled " De THomme " was published after his death. The climax was reached by Baron d'Holbach in his " Syst^me de la Nature," in which Materialism, fatalism, and atheism wei'e openly avowed. According to this system matter and motion are eternal ; thought is an agitation of the nerves ; the soul the result of our corporeal^ organization ; the will the strongest sensation ; the ground of morals a regard to our own happiness. There is no freedom, no morality, no future existence, no God. When these principles got hold of the popular mind, then came the end.
D. Positivism.
Comte, the author of the " Positive Philosophy," was born in 1798, and died in 1859. The greater part of his life was passed in poverty and neglect. His only occupation was teaching. Ten years were devoted to the preparation of a course of lectures on philosophy which secured him wealth and fame. He called his system " Philosophie Positive," because it purported " to assume nothing beyond the content of observed facts."
The fundamental principle of the " Positive Philosophy " is the one so often referred to, namely, that the senses are the only source of our knowledge, hence nothing exists but matter. There is no mind distinct from matter ; no such thing as efficiency ; no causes, whether first or final ; no God ; no future state of existence for man. Theology and psychology are, therefore, banished from the domain of science. Science is solely occupied in the observation of facts, and in deducing from them the laws by which they are determined. These laws, however, are not forces operating in a uniform manner, but siniply statements of the actual order in the sequence of events. This sequence is not only uniform but neces- sary. Our business is simply to ascertain what it is. The only method by which this can be done is observation. This task is
1 F. Fabri in Herzog's Real-Encychpadie, art. " Materialismus."