LECTURE I.

THE DISTINCTION BETWEEN PHYSICAL AND METAPHYSICAL

SCIENCE.

THE subject which I have undertaken to consider in these lectures, not without a painful sense of my own incompetency for the task, is the oldest, the most comprehensive, and the most important, that has ever tasked the human faculties. Upon the answers to the great questions that are involved in it depend all our knowledge, all our duties, and all our hopes. In no age of the world, of which we have any clear and trustworthy record, in no condition of the human race, save that of the lowest forms of barbarism, have these questions ceased to occupy, in a greater or less degree, the attention of man, and to influence his conduct. In one point of view, they may be said to require the most profound learning and the largest scope of intellectual ability in him who would consider and discuss them to advantage; in another aspect, they seem to come within the sphere of the narrowest intellect, and to offer the plainest and most practical considerations to every member of the human family. And herein lies a sufficient apology for what might otherwise appear an act of presumption, the attempt on the part of an individual, however humble and unfitted for the task by the lack of professional training, not merely to form clear ideas for himself upon these subjects, but also to endeavour to impress them upon others. For they are matters of immediate and universal concern; the duty of examining our opinions respecting them is incumbent

upon all, under an awful weight of responsibility, if not to the full extent for the correctness of our conclusions, at any rate for the diligence, earnestness, and fidelity with which we have prosecuted the inquiry. The imposing names of Philosophy and Theology do but cover up those direct and momentous questions, which even the most incurious disposition at times must ask, What must I believe, and upon what standard, or by what authority, must I regulate my conduct? All other things are of temporary, these are of eternal interest.

And this duty of examination is one which is perpetually renewed, as from age to age the nature of the problem shifts, or we encounter new difficulties in the way of the inquiry, proceeding from new habits of thought, from the progress of science and speculation, and from the altered relations of man to man which spring from political changes and new forms of society. The evidences of religious truth need to be constantly taken up anew, and presented under a variety of aspects, to suit the changing emergencies of the times. Political fanaticism sometimes turns its destructive rage against the institutions of our faith; new doctrines in philosophy, proposed at first as mere exercises of fancy, gradually harden into fixed dogmas, and secretly undermine the foundations of belief; and, lastly, the natural allies of religion, perverted by malign influences, sometimes become its opponents, and the cause of divine truth suffers from the fanaticism of philanthropy and reform. Against all these enemies, which often carry on their warfare, not from without, but in the silence of his own meditations, the believer needs to be constantly armed, if he would not have his faith degenerate into a mere prejudice, or shield itself under the hard covering of a stern and irrational dogmatism.

According to the common notion, Philosophy and Theology are sister sciences, so closely allied that it is often difficult to make a distinction between them. Every person must hold some opinions relative to each, and these opinions form two mutually dependent creeds, which may be, in a greater or less degree, peculiar to himself, and of which the action and reaction are so

nearly equal that it is often difficult to determine which is the parent of the other. Every theory respecting the origin and first principles of human knowledge must bear a close relation to that subject in regard to which knowledge is of the highest value, the doctrine of God, duty, and immortality. The religion of the Greeks and Romans, so far as it existed in a definite and consistent form, that is, as it was conceived by enlightened and thinking men among them, was wholly drawn from their philosophical tenets, or, more properly speaking, it was identical with those tenets. And so it has been in modern times. Skepticism in philosophy and skepticism in religion, if not the same thing, at least usually go together.

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 it from all investigation, and not infrequently discoveries in science are denounced, if they are at variance with the supposed dictates of revelation. If metaphysics are made a test of the truth of Chris

tianity, 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 lecture. We must begin with definitions, and if these appear somewhat abstruse at first, I hope they will become clearer as

we go on.

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.

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.

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 compre