It is in the name of science and by the processes of science that the Spiritualists of the nineteenth have combated the Sensualists of the eighteenth century. They have not, it is true, absolutely crushed Materialism, that child and legitimate heir of Sensualism; but while dethroning the parent, they have compelled the child sometimes to avow himself boldly, sometimes to transform himself, and to assume other features and other arms than those of his cradle. I will only cite the lecture of M. Cousin on the "Sensualistic Philosophy in the Eighteenth Century," and the essay of the Duke de Broglie on the "Existence of the Soul," [Footnote 37] written on the occasion of the work of M. Broussais: "De l'Irrritation et de la Folie." [Footnote 37: This essay, first inserted in 1828 in the Revue Française, has been reprinted in the "Ecrits et discours divers" of the Duke de Broglie, collected and published in 1863.] {228} Whoever, after having read them, would still persist in maintaining the Sensualism of Locke and of Condillac, or in refusing to see the consequences to which Sensualism leads, would prove, in my opinion, that he has not understood either the question put, or the doctrine combated and refuted. We have here a result acquired for the science of the intellectual world, and we owe the result to the polemics of the spiritualistic school. That school has obtained another result more important still, and which belongs no longer to the polemics of simple negation, but to positive doctrine; it has set in the broad light of day the real and fundamental principle of morals, the distinction as to the essentials of moral good and evil, as well as the law of obligation, that "categorical imperative," the sole refuge which Kant found against Skepticism. 229 Neither the interest well defined of each individual, nor the interest of the greater numbers, nor any sentimental sympathy, nor any system of positive written law, can, for the future, be considered as the basis of morals. An attempt is made in the present day to establish another thesis, and to represent morality as absolutely independent of religion. Grave error, which discards from morality, if not its principle, at least its source and its object, its author and its future; an error, however, very different from those errors which dispense even with the principle of morals, and assign as the rule for the conduct of men, motives having in themselves nothing moral, nothing absolute. The fact that man's conscience and man's reason recognize the distinction of moral good and evil, and at the same time the duty of practicing that good as the law of human actions, is a fact which we may now regard as acquired to philosophy. {230} The treatise "Du Bien," in the work of M. Cousin upon "Le Vrai, le Beau, et le Bien," the preface of M. Jouffroy to the "Outlines of Moral Philosophy," by Dugald Stewart, and the "Essia sur la Morale," in the "Mélanges Philosophiques," which M. Jouffroy