jects which Milton assigned for contemplation to one band of the spirits fallen from heaven, who, in their place of punishment, 66 apart sat on a hill retired, In thoughts more elevate, and reasoned high All science proceeds from one generalization to another, and must therefore end at a point, in a science that surveys the basis of all the others, determines their proper relations, and binds the whole into one orderly system of knowledge. This seems to have been Lord Bacon's conception of the matter, when, in his general scheme of knowledge, he says, "The basis is Natural History, the stage next the basis is Physics, the stage next the vertical point is Metaphysics." To examine in turn all the questions with which metaphysical philosophy is conversant, so as to exhibit their abstract character, would be a long and, it may be, an unprofitable undertaking. I shall not attempt it, as the fact, perhaps, is apparent enough from a mere enumeration of the subjects, and because all of them which are immediately connected with my principal theme will come up for subsequent consideration. It will be enough for the present briefly to allude to a few of them, the purely ideal character of which may perhaps be questioned. And here a distinction is to be made, as one portion of what is usually called the philosophy of mind is certainly occupied with matters of fact, and comes within the province of inductive reasoning. Psychology is the latest designation in use, and perhaps the most convenient one, for that science which bears the same relation to mind that Anatomy and Physiology do to our corporeal nature. Certainly there are facts of consciousness, no less than those which are evident to sense; the human mind, to a certain extent, is a subject of observation and experiment, as the supposed seat or origin of various phenomena that admit of number, arrangement, and classification. These phenomena, again, are not produced fortuitously, or at random, but are subject to fixed laws, more or less obvious, that may be definitely expressed. I need only refer to the great laws of association, or suggestion, which every one has occasion to observe who seeks to call up subjects that are related to each other, or to discipline his memory. The phenomena of mind, also, are often complex, and need to be analyzed and reduced to their simplest elements. Imagination, for instance, is a compound faculty, embracing simple suggestion, conception, or the picturing forth of an object, abstraction, and the power of forming novel combinations from the elements thus obtained. I speak of this science as confined entirely to mind, without forgetting that one important point in it is the question, whether there be any such separate existence as mind distinct from matter. If this question be determined in the negative, it would appear, at first sight, that no division can be made, that there is no room for any science separate from that which treats of the laws and properties of bodies. Yet the subject is not really affected by the determination of this doubt. Every one is conscious of thinking, reasoning, willing, of pleasure, love, and hatred; and these qualities or phenomena are wholly unlike bulk, figure, extension, and other qualities usually attributed to matter. Now we do not need to assume, in the outset, that there is a separate existence, or entity, in which the first class of these attributes inhere. There is no doubt that the two sets of phenomena are perfectly distinct from each other; there is no danger of confounding them. Avoiding all hypotheses and mooted questions, therefore, it may be said that psychology, treating of those facts which we learn from consciousness, is a branch of physical science, the other subdivisions of which relate to those facts which come to our knowledge through the senses. But it is certainly no part of psychological inquiry to seek after the origin of our notion of cause, or to analyze our idea of infinity. Observation cannot aid us here. In the external world, and in the succession of our thoughts, we witness only events or changes; we observe only sequences of phenomena; and to bind together the two terms of a sequence in the relation of cause and effect is the work of pure reason, unaided by the perceptive faculty. So, also, whatever we observe, whether in external nature or in the world within us, is finite, limited, and contingent; the idea of infinity is superadded by reason, transcending the sphere of sense and reflection, and baffling even the power of the imagination to seize or comprehend it. Our ideas, moreover, of space and time are abstract conceptions, which rise, indeed, on occasion of experience, but cannot be deduced from experience, nor explained by its teachings. To speculate on these things is the work of metaphysical philosophy properly so called, of that science which goes beyond facts to principles, which begins from intuitions and ends in demonstrative certainty. It may be said, however, that metaphysical inquiries are not concerned exclusively with relations of ideas, since Ontology, which is an important and the most abstruse branch of this science, relates avowedly, and as its name imports, to real entities, which are conceived to exist out of the mind, or independently of thought. I answer, that the realities which are the objects of ontological inquiry are few in number, and though supposed to exist out of the mind, they are known to us only as abstract conceptions; and the sole purpose of ontology, the only problem which it attempts to resolve, is the question whether they are realities or not. This point cannot be ascertained by observation and experiment, which are the great instruments of physical inquiry; it can be determined only by studying the relations of our ideas. Take, for instance, the idea of material substance, which we conceive of only as the unknown something that supports and manifests certain qualities, even these qualities being known to us only as the hidden causes of certain sensations, or states of mind; and this idea, these states of mind, are the only media the study of which can furnish an answer to the question as to the reality of this substance. Aristotle calls this substance "the primary matter," to distinguish it from the secondary forms of matter, that are the only objects of which we take cognizance through the senses. "The primary matter," he says, "is that without which nothing could formally exist. It is neither earth, nor air, nor fire, nor water. It is neither hot, nor cold, nor dry, nor moist, nor solid, nor extended. It is the universal element, but can never become objective to sense." How, then, can we obtain a view of this elementary being? "We gain a glimpse of it," says the learned author of Philosophical Arrangements, by abstraction, when we say that the first matter is not the lineaments and complexion, which make the beautiful face; nor yet the flesh and blood, which make those lineaments and that complexion; nor yet the liquid and solid aliments, which make that flesh and blood; nor yet the simple bodies of earth and water, which make those various aliments; but something which, being below all these, and supporting them all, is yet different from them all, and essential to their existence." Certainly, this idea is a pure abstraction, quite as much so as the infinitesimal quantities of the algebraist; and though reality may be predicated of it, if we believe in its existence, it is only in the same sense in which quantities infinitely small may be said actually to exist anywhere in measurable extension. "We obtain a sight of it [metaphorically] when we say, that as is the brass to the statue, the marble to the pillar, the timber to the ship, or any one secondary matter to any one peculiar form, so is the first and original matter to all forms in general." Obviously, a dim analogy like this affords very insufficient ground for a physical investigation; and the whole subject must be put over to the department of metaphysical science.* And here, it may be observed in passing, we have an illustration of the radically vicious method in which the ancients undertook the study of nature; - omitting altogether the observation of particular facts, and seeking to deduce from grand but vague abstractions, like this of "the primary matter," the individual truths which they disdained to collect from patient induction. It was as if a botanist should attempt to evolve by meditation the * The quotations in this paragraph are taken from Sir W. Drummond's Academical Questions, a metaphysical work of some repute forty years ago. grand archetypal idea of a plant, from which to deduce by logical analysis and strict demonstrative reasoning the several forms which all existing plants must assume. We ought not rashly to infer that there is no longer any danger of committing flagrant mistakes like this in the pursuit of knowledge. Error tends to come round in cycles; and the reaction against the Baconian method, to which I alluded in my last lecture, has given some currency to speculations in natural science which seem the legitimate descendants of the reveries of the schoolmen. I need not go for illustration to a scheme so extravagant as the system of natural history which was devised by Oken, a philosophical pupil of Schelling, which still has many disciples and followers in Germany, though Menzel, himself a favorer of it, acknowledges that it "corresponds perfectly to the philosophy of Paracelsus and the Rosicrucians in the Middle Ages." I find a more respectable instance in the infant science of Morphology, applied to animals by St. Hilaire, and to plants by Goethe, and which has recently been made popular, at least in some of its applications, by the author of the Vestiges of Creation. According to this speculation, "plants and animals, in the process of growing up from their germs, have a tendency to develop themselves in a much more uniform manner than they in fact do, and the differences-for example, of leaf, flower, and fruit-are mere modifications of one general phenomenon." The theory assumes that the type, or grand purpose of nature, though constantly struggling to manifest itself, is realized only in a few cases, which are admitted monstrosities, the system resting on these, and the induction from a few anomalous instances thus overriding the conclusion derived from the great majority of cases. The doctrine naturally succeeds, that all the races of animals tend, as it were, to pass into each other, in their progress to or from the typical creature, which forms either the commencement or the end of the scale. The distinctions of species thus disappear, races cease to be permanent, and man acknowledges fraternity, or a common pedigree, with the reptile and the brute. A purely speculative notion is here superinduced upon the inductions of experience, though a lingering |