By the side of the philosophy of Locke, there is one much greater, which it is important to preserve from all exaggeration, in order to maintain it in all its height. Founded in antiquity by Socrates, constituted by Plato, renewed by Descartes, idealism embraces, among the moderns, men of the highest renown. It speaks to man in the name of what is noblest in man. It demands the rights of reason; it establishes in science, in art, and in ethics fixed and invariable principles, and from this imperfect existence it elevates us towards another world, the world of the eternal, of the infinite, of the absolute.

This great philosophy has all our preferences, and we shall not be accused of having given it too little place in these lectures. In the eighteenth century it was especially represented in different degrees by Reid and Kant. We wholly accept Reid, with the exception of his historical views, which are too insufficient, and often mixed with error.[273] There are two parts in Kant,—the analytical part, and the dialectical part, as he calls them.[274] We admit the one and reject the other. In this whole course we have borrowed much from the Critique of Speculative Reason, the Critique of Judgment, and the Critique of Practical Reason. These three works are, in our eyes, admirable monuments of philosophic genius,—they are filled with treasures of observation and analysis.[275]

With Reid and Kant, we recognize reason as the faculty of the true, the beautiful, and the good. It is to its proper virtue that we directly refer knowledge in its humblest and in its most elevated part. All the systematic pretensions of sensualism are broken against the manifest reality of universal and necessary truths which are incontestably in our mind. At each instant, whether we know it or not, we bear universal and necessary judgments. In the simplest propositions is enveloped the principle of substance and being. We cannot take a step in life without concluding from an event in the existence of its cause. These principles are absolutely true, they are true everywhere and always. Now, experience apprises us of what happens here and there, to-day or yesterday; but of what happens everywhere and always, especially of what cannot but happen, how can it apprise us, since it is itself always limited to time and space? There are, then, in man principles superior to experience.

Such principles can alone give a firm basis to science. Phenomena are the objects of science only so far as they reveal something superior to themselves, that is to say, laws. Natural history does not study such or such an individual, but the generic type that every individual bears in itself, that alone remains unchangeable, when the individuals pass away and vanish. If there is in us no other faculty of knowing than sensation, we never know aught but what is passing in things, and that, too, we know only with the most uncertain knowledge, since sensibility will be its only measure, which is so variable in itself and so different in different individuals. Each of us will have his own science, a science contradictory and fragile, which one moment produces and another destroys, false as well as true, since what is true for me is false for you, and will even be false for me in a little while. Such are science and truth in the doctrine of sensation. On the contrary, necessary and immutable principles found a science necessary and immutable as themselves,—the truth which they gave as is neither mine nor yours, neither the truth of to-day, nor that of to-morrow, but truth in itself.

The same spirit transferred to æsthetics has enabled us to seize the beautiful by the side of the agreeable, and, above different and imperfect beauties which nature offers to us, to seize an ideal beauty, one and perfect, without a model in nature, and the only model worthy of genius.

In ethics we have shown that there is an essential distinction between good and evil; that the idea of the good is an idea just as absolute as the idea of the beautiful and that of the true; that the good is a universal and necessary truth, marked with the particular character that it ought to be practised. By the side of interest, which is the law of sensibility, reason has made us recognize the law of duty, which a free being can alone fulfil. From these ethics has sprung a generous political doctrine, giving to right a sure foundation in the respect due to the person, establishing true liberty, and true equality, and calling for institutions, protective of both, which do not rest on the mobile and arbitrary will of the legislator, whether people or monarch, but on the nature of things, on truth and justice.

From empiricism we have retained the maxim which gives empiricism its whole force—that the conditions of science, of art, of ethics, are in experience, and often in sensible experience. But we profess at the same time this other maxim, that the foundation of science is absolute truth, that the direct foundation of art is absolute beauty, that the direct foundation of ethics and politics is the good, is duty, is right, and that what reveals to us these absolute ideas of the true, the beautiful, and the good, is reason. The foundation of our doctrine is, therefore, idealism rightly tempered by empiricism.

But what would be the use of having restored to reason the power of elevating itself to absolute principles, placed above experience, although experience furnishes their external conditions, if, to adopt the language of Kant,[276] these principles have no objective value? What good could result from having determined with a precision until then unknown the respective domains of experience and reason, if, wholly superior as it is to the senses and experience, reason is captive in their inclosure, and we know nothing beyond with certainty? Thereby, then, we return by a detour to skepticism to which sensualism conducts us directly, and at less expense. To say that there is no principle of causality, or to say that this principle has no force out of the subject that possesses it,—is it not saying the same thing? Kant avows that man has no right to affirm that there are out of him real causes, time, or space, or that he himself has a spiritual and free soul. This acknowledgment would perfectly satisfy Hume; it would be of very little importance to him that the reason of man, according to Kant, might conceive, and even could not but conceive, the ideas of cause, time, space, liberty, spirit, provided these ideas are applied to nothing real. I see therein, at most, only a torment for human reason, at once so poor and so rich, so full and so void.

A third doctrine, finding sensation insufficient, and also discontented with reason, which it confounds with reasoning, thinks to approach common sense by making science, art, and ethics rest on sentiment. It would have us confide ourselves to the instinct of the heart, to that instinct, nobler than sensation, and more subtle than reasoning. Is it not the heart, in fact, that feels the beautiful and the good? Is it not the heart that, in all the great circumstances of life, when passion and sophism obscure to our eyes the holy idea of duty and virtue, makes it shine forth with an irresistible light, and, at the same time, warms us, animates us, and gives us the courage to practise it?

We also have recognized that admirable phenomenon which is called sentiment; we even believe that here will be found a more precise and more complete analysis of it than in the writings where sentiment reigns alone. Yes, there is an exquisite pleasure attached to the contemplation of the truth, to the reproduction of the beautiful, to the practice of the good; there is in us an innate love for all these things; and when great rigor is not aimed at, it may very well be said that it is the heart which discerns truth, that the heart is and ought to be the light and guide of our life.