This, I say, is the common view of the subject; and we might therefore well expect, what often happens, that the claims of the two sciences, so called, should seriously conflict. Men are drawn different ways by opposite fears, by their dread, on the one hand, of an irreligious philosophy, and on the other, of an unphilosophical religion. Loyalty to truth, which is the highest claim that can be made upon human reason, is drawn into open hostility with our sense of duty to God, which is the most awful and imperative of all obligations. The course of the student of science, the honest and sincere inquirer after knowledge, often appears adverse or injurious to the feelings or the faith the prejudices, if you like- of the religious believer, the devout worshipper of an Omnipotent Father and Friend. And even where direct opposition is avoided, a disputed claim to precedence is set up, and sometimes brings with it an intolerable burden of anxiety and doubt. On the one hand, it is maintained that every religious creed must be tried at the bar of human science, and its doctrines accepted or rejected according to their agreement with the speculative dogmas which the unaided reason has evolved as the limits and criteria of truth; on the other, the sacredness of the subject is unwarily held up to shield theology from all investigation, and, not infrequently, discoveries in science and theories in philosophy are denounced, if they are at variance with the supposed dictates of revelation. If metaphysics are made a test of the truth of Christianity, it seems but equal justice to make Christianity a test of the correctness of metaphysics. Sometimes a compromise is proposed, which is no less shocking to the feelings of the believer than a contumelious rejection of his faith. Philosophy is represented as candid and liberal; as superseding religion, it is true, in the minds of the cultivated and reflecting classes, but continuing to respect it, as an imperfect likeness of itself, in the bulk of mankind. According to this theory, there are many stages of progress for the human intellect, and men pass on from religion to philosophy, as they do from barbarism to civilization.

Now, before conflicting claims like these can be reconciled, it is necessary to get clearer ideas of the subjects of dispute, to

determine their respective boundaries, to see how far, if at all, they encroach, upon each other, and, if possible, to settle the logic of the inquiry. Perhaps it will be found, after all, that the provinces of Philosophy and Theology are entirely distinct, so that there is no proper interference, and no cause for controversy between them. To establish this point is the object of the present chapter. We must begin with definitions, and if these appear somewhat abstruse at first, I hope they will become clearer as we go on.

Classification of the objects of Knowledge. The simplest, as well as the most comprehensive, classification of all objects of knowledge, is that which separates them into relations of ideas and matters of fact. I borrow the language of him who was at once the most subtile logician and the most consistent skeptic of modern times: "All the objects of human reason or inquiry," says Hume, "may naturally be divided into two kinds, to wit, Relations of Ideas and Matters of Fact." This coincides very nearly with the familiar distinction between physics and metaphysics, except that the meaning of the latter must be so far extended as to embrace the cognate sciences of grammar, logic, and mathematics. Stating the proposition in other words, we say that all science may be reduced to two branches: 1. The study of things physical, or those which exist distinct from our thoughts; 2. The study of things metaphysical, or those which do not exist apart from our thoughts.

No one can fail to see an essential difference between a fact and an abstraction, or a pure idea, like that of cause, goodness, power, existence, and the like. The former is an object of sense, something which can be seen, heard, felt, or touched, whether we have had sensible evidence of it ourselves, or rely upon the testimony of others who have had such evidence, or infer its existence from inductive reasoning, or from the presence of its effects. The latter is a pure mental conception, which has no existence except in relation to the mind which forms it. Such conceptions are called realities only by a figure of speech; they are so called to mark our strong sense of the correctness with which a certain quality is attributed to a substance or an action.

Thus, virtue is said, figuratively, to be a reality, only to mark our firm belief that there are such things as virtuous actions. In this class must be ranked all the abstractions of the geometer and the algebraist. There are no such things in nature as circles and triangles; the only proper realities are circular objects and triangular objects.

Two classes of matters of fact. But the nature of these abstractions may be most clearly apprehended by considering, in the first place, what we mean by matters of fact. These may be distinguished into things which exist, and events which take place. All the objects of natural history and physical science stones, shells, plants, and animals are ranked in the former class; all the laws, so called, of physical science, the laws of motion, for instance, all the habits observed by the naturalist, such as the modes of growth and reproduction of plants and animals, are comprehended in the latter. Both alike are matters of fact. It is a fact that the earth exists, or is; it is equally a fact that the earth moves. That there is a sun in the heavens is a fact of one order; that this sun illumines objects on the earth is a fact of a different order, it is an event which takes place. We have sensible evidence of both.*

Mode of inquiry and reasoning about abstract ideas. — I am dwelling too long, perhaps, on a very familiar distinction; but it is one that is fundamental to the present inquiry, which cannot proceed without the fullest and clearest comprehension of it. These two classes, which comprehend all objects of knowledge, are distinguished from each other, not merely by the broad and obvious lines of distinction inherent in their nature, which have been already explained, but by radical differences in the modes of inquiry and reasoning which are respectively

"The communication of this kind of knowledge," says Whateley, "is most usually, and most strictly, called information. We gain it from observation and from testimony. No mere internal workings of our own minds (except when the mind itself is the very object to be observed), or mere discussions in words, will make a fact known to us.” — Logic, p. 268.

that is, of abstrac

applicable to them. The relations of ideas tions, or pure ideas are made known to us by intuition or reflection; and reasoning about them proceeds by the demonstrative method, the conclusions at which we arrive being absolutely certain. According to the absolute laws of the human understanding, I speak it reverently, it is not within the power of Omnipotence to disprove these results, or even to render them doubtful. Their falsity would involve a contradiction; to maintain that they are untrue, is to say, that it is possible for a thing to be and not to be at one and the same moment. All the truths of pure mathematics, pure logic, and pure reason are metaphysical truths, and we can no more doubt them than we can question the accuracy of the multiplication table. Their falsity is inconceivable. This attribute of logical certainty proceeds from the pure, abstract, and perfectly simple or uncompounded nature of the ideas which enter into such reasoning. These ideas are pure creations of the intellect; in their uncompounded and abstract character, they are not derived from observation, and are therefore not perverted by that great source of error, the imperfection of our senses, or the limitations of our power of perception. When we entertain these ideas, or reason about them, the mind is closed to all outward impressions, and freed even from the memory of their former occurrence.' The ideas that are contemplated, then, are contemplated in their entireness; for, being uncompounded, if they are apprehended at all, they must be perfectly apprehended, and consequently the relations between. them are discerned at once, or by intuition. Demonstrative reasoning proceeds by a series of such intuitions, and hence the absolute character of its results. If the chain of such reasoning be too far extended, indeed, without a system of notation, the

*"A clever man," says Sir J. Herschel, "shut up alone, and allowed all unlimited time, might reason out for himself all the truths of mathematics, by proceeding from those simple notions of space and number of which he cannot divest himself without ceasing to think; but he could never tell by any effort of reasoning, what would become of a lump of sugar if immersed in water, or what effect would be produced on his eye by mixing the colors yellow and blue."

imperfections of memory may come in, some steps may be forgotten, and mistakes will be committed. But this cause of error never affects a simple intuition, or a step in the process when taken by itself. Here the certainty is absolute.

Mode of inquiry and reasoning about matters of fact.- Now, what is the method of inquiry or procedure for the other class of objects of knowledge, - for matters of fact? We enter upon totally different ground here. Instead of abstractions, we have realities; instead of shutting out sensible evidence altogether, we are obliged to rely upon it exclusively; instead of intuitions, we have observations and experiments; instead of demonstration, we have induction; instead of the objects of inquiry being perfectly simple and uncompounded, they are made up of an unknown and unknowable number of elements and qualities; and instead of arriving at conclusions which are absolutely true, we gain those only which are morally certain. I speak now of both kinds of matters of fact,— both of things which exist, and of events which take place. The imperfections of the senses come in here to their full extent, as causes of possible error. The objects of physical science must always be imperfectly known; we never can be sure that our analysis of them is complete, or that our observation has taken in all their outward qualities. The attractive power of the loadstone was known for ages before its attribute of polarity was discovered; yet what is apparently more simple and obvious than this quality, which can be detected at once by floating a magnet on a piece of cork in a basin of water? Down to the times of Watt and Cavendish, water was supposed to be a simple element, and it figures as such in some of the most remarkable of the ancient theories of cosmogony; these chemists, about a century ago, discovered that it was compounded of two gases. But it is useless to multiply instances. The chemist will tell you that it is not impossible, that it is even probable, that every one of the sixty substances now counted as elementary will ultimately be decomposed. Of course, the vast number of compounded objects of which Natural History takes cognizance are still more imperfectly known in their qualities and relations, than those substances