But this complete science is not within the reach of mortal man, and in its absolute perfection belongs alone to God.
Fettered by his nature, and fettered still more by the conditions of his earthly existence, man can only aspire to a partial science; and it is left him to choose in this immense sphere that particular ground whereon to pursue his investigations with more profit. The entire field is open to us. “God,” says the Scripture, “has delivered the world to the searchings and the disputes of men.” In bestowing on us the faculty of finding a reason for things, he has authorized us to make use of this faculty in regard to all the truths of the natural order, provided we see on all sides the boundary of the mysterious, which reminds us of our essential infirmity.
But though every science is equally lawful, they are not all equally useful. We may divide them into three classes, which form the three circles of the great sphere of truth. There are the sciences which concern the inferior world, the mathematical and physical sciences; those whose object is humanity, the psychological and moral sciences; thirdly, those which concern the higher world, the science of first principles and of the primal cause of all things. This last, which holds the centre of the great sphere of truth, is called metaphysics; and it is joined to the psychological and moral sciences, which are drawn from the same principles, under the common name of philosophy.
This simple statement of the place which belongs to philosophy in the hierarchy of the sciences is enough to prove our thesis, namely, the necessity of philosophy for the formation of the true savant.
What man, in fact, is truly worthy of this name, unless it be he who is possessed of the necessary science? But I would ask: Does that man possess this science, does he know what he ought to know, who possesses a perfect knowledge of the inferior world, and who ignores himself; who has passed his life away in studying the laws of bodies, yet has never given a thought to his own nature and the destiny of his own soul? Tell me that that man is a great physicist, and I will not gainsay it; but I can never consent to your bestowing on him the title of a man of science. The ancient Greek unites with me in denouncing an error so opposed to the dignity of the human intelligence. “Know thyself.” Such was the precept impressed on all those who went to Delphi to consult the oracle of Apollo. The gate of the true temple of wisdom opens only to those who have put this recommendation into practice. But wisdom is the true science. The true scholar is not he who knows something, but he who knows enough of it. No one thinks of praising unreservedly a statue whose head and bust are scarcely outlined, and whose lower members alone are finished. It is to the whole, it is above all to the principal parts, that we look, when we wish to estimate a work definitely. Reason commands that we act in the same manner when we wish to judge of the absolute value of an intelligence. As there are for a people liberties which are necessary, so is there also for a man knowledge which is indispensable, of his own nature, his origin, and his destiny; and he who is deprived of this, although he possess all sorts of superfluous knowledge, cannot pretend to the title of a man of science.
To this first motive for the necessity of philosophy derived from its object we are able to add another deduced from the very idea of science. Science, we have said, is the knowledge of things by their principles. Its perfection consists in attaching particular truths to truths which are more general, which comprise them, and which enable the intelligence to catch them at a single glance. But this unity, which forms the perfection of the sciences, and which each of them establishes among the particular truths which constitute their several objects, it is the province of philosophy to establish among the sciences themselves. Metaphysics, in fact, which is the principal part of philosophy, has for its special object not the study of particular truths, but of those general principles which throw a light upon the other sciences. It is then their necessary complement, and their indispensable crown. Set in the very centre of the great sphere of knowledge, it is to the other sciences the polar star, whereon they must turn their eyes in order to see their way. It points out to each one of them the relation of the truths which constitute their special object with the primary truth which is their common centre. The geometrician and the physicist, who occupy themselves exclusively with the relations of numbers and the laws of bodies, are like explorers voyaging in regions where the disc of the sun is never seen, placed without the power of tracing to their luminous focus the rays of truth which their studies permit them to catch.
But far beyond this, philosophy alone can make the geometrician or the physicist acquainted with the inner essence of the objects which form the special material of their studies. Geometry analyzes the relations of magnitudes, but it does not seek to give an account of the very idea of magnitude: natural philosophy evolves from experiments the laws of bodies; but it cannot, by induction at least, which is its special process, arrive at a knowledge of the essence of bodies. Philosophy alone scrutinizes, as far as it is possible for human reason so to do, the mystery of that inner essence by which each thing is what it is. Philosophy is therefore necessary for the completion of the special sciences, and to furnish scholars with the knowledge of their different objects.
Lastly, a fourth and still more incontestable motive for the necessity of philosophy for the formation of the true scientist is deduced from the scientific education of the intelligence, which philosophy alone is capable of undertaking. One of the most important parts of philosophy is logic; that is, the science of reasoning, and of the different processes by means of which the human intelligence can find truth. These processes are not only those which philosophy avails itself of, but also those which obtain among the other sciences. It belongs to philosophy, and to philosophy alone, to study their nature, to fix their laws, to prevent their wandering. The other sciences borrow these processes from it; they make use of them; but they would depart from their object if they studied them in themselves. One cannot, then, dispute the utility of philosophy for the formation of the scientist, without maintaining an evident absurdity; to wit, that it is useless for the workman to obtain a knowledge of the instrument he uses in the exercise of his craft. Who can fail to see that, without a profound knowledge of the different intellectual processes, the scientist is exposed to a double danger—on the one hand, to the danger of deceiving himself in the use of the special process which is proper to him; on the other, to the danger of exaggerating its importance, and not holding in sufficient estimation those processes equally legitimate which are in use among other sciences? The first of these dangers is to be feared, above all, in the inductive sciences. Induction is a mode of reasoning perfectly legitimate in itself; but of all the intellectual processes it is the one which is most easily abused, and which, pushed beyond its just limits, may lead to the gravest of errors.
The mathematical sciences which work by equation are not equally exposed to the danger of diverging from their track, but they threaten with a still greater peril the mind of the scholar whom the study of philosophy has not set on his guard against the too exclusive influence of this process. Equation, as its name indicates, does not pass from one truth to another, but from a like to a like, from the expression of a relation of number or magnitude to another simpler expression of the same relation. It is not, then, surprising that this process offers to the mind an exactness far more easy of comprehension than that by means of which we are enabled to grasp moral truths and give ourselves a reason for our own nature. The philosophic mathematician will take this difference perfectly into account, and his progress in the science of numbers will hinder him in no wise from seizing upon substantial truths. But the man who all his life long has occupied himself with nothing save the study of mathematics is very much exposed to becoming incapable of comprehending that which is not demonstrated by equation; and he will experience a greater estrangement and inaptitude for the science of God and of himself in proportion as he advances further in the science of the inferior world.
In good faith, can we see progress in this? Is it not, on the contrary, a degradation, not only from the moral, but also from the intellectual point of view? Has not the absence of a sound philosophy stood as much in the way of that man’s scientific elevation as of his moral greatness? Though he may have become a more able manipulator of formulas, he surely has not become a greater savant. Nothing, on the contrary, is more calculated to cramp and mutilate the faculties of the soul than this exclusive concentration on one of the collateral objects of its activity. In the same way as a limb which is never set in motion wastes away and becomes paralyzed, so the powers of the soul cannot cease to act without losing their vigor. Such is the state to which a too exclusive study of what are called the exact sciences reduces certain minds: these are the minds whose higher faculties have been wasted. All their activity is turned to one side; the eye of their intelligence is so constructed for the lesser light of equation, that, when they rise from the subterranean world of geometrical abstractions to enter into the region of moral realities and into the world of souls, they are dazed, and can see naught but darkness. True it is that they are much enamored of their blindness, and attribute it to excess of light. Fain to acknowledge that their formulas, the only legitimate arguments according to them, are powerless to solve the great moral problems, they suppress those problems with the declaration that it is folly in human reason to trouble itself with them, and that for him who wishes to ascertain truth and possess certainty it is enough to study the relations of numbers and the laws of bodies. Such is true science in the eyes of the disciples of Auguste Comte. These men are perfectly logical. They adopt the only means to ensure their title to be really scientific men without the aid of philosophy; they suppress philosophy altogether, and suppress consequently its object, that is, the human soul and God, the beginning and the end of things. With adversaries of this stamp I refuse to dispute. I can only appeal to their conscience against the disdain which their lips affect for the formidable questions whose suppression they in vain decree. They exist in spite of them; and wherever they go they carry about in themselves the problems which they refuse to examine. As for those for whom God and the soul have still a meaning, I believe I have said enough to compel them to admit that no one has a right to the title of a wise man so long as he ignores the science which learns all that reason can know of those grand objects, and that the other sciences when separated from it are often more hurtful than useful to the real improvement of the intellect.