INTRODUCTION. CHAPTER I. ON THE NATURE AND IMPORTANCE OF MENTAL SCIENCE § I.-NATURE OF THE SCIENCE. Menta Philosophy, what.-What is Mental Philosophy, as distinguished from other branches of science? Philosophy, in the wide sense usually given it, denotes the investigation and explanation of the causes of things; it seeks to discover, and scientifically to state, the general laws both of matter and mind; its object is to ascertain facts, and their relation to each other. Mental Philosophy has for its object to ascertain the facts and laws of mental operation. Metaphysics, what. Of the two grand departments of human knowledge—the science of matter and the science of mind the former, comprising whatever relates to mate rial phenomena, the science of nature, is known under the general name of Physics; the latter, the science of mind, is often designated by the corresponding term, neither very correct nor very fortunate, Metaphysics. This term is often used to include whatever does not properly fall under the class of Physics. In its strict sense, it does not include so much, but denotes properly the science of abstract truth; the science of being, in itself considered apart from its - particular accidents and properties-that which we now call Ontology. The term is commonly ascribed to Aristotle, but incorrectly. It originated with his followers. Several treatises of his relating to natural science having been col lected and published, under the title Ta voika, other treatises on philosophical subjects were afterward arranged under the title тa μɛтa qvoika, indicating their relation to the former, as proper to be read after the perusal of those Hence the term came into use in the general sense, already spoken of, to denote whatever is not included under physics although originally employed with a much more limited meaning. Mental Philosophy not properly Metaphysics.-- Neither in its wider nor in its stricter sense does this term properly designate the science of mind. Mental Philosophy neither embraces every thing not included under physics, nor is it the science of abstract being. As one of the intellectual, in distinction from the physical sciences, it holds a place along with Logic-the science of the laws of human thought and reasoning; Ethics-the science of morals; Politics-the science of human organization and government; to which should be added Ontology-the science of pure being; all which are properly embraced under the term Metaphysics in its wider and popular sense. To designate the science of mind in distinction from these other sciences, some more definite term is required. The word Psychology is now corning into use as such a term. Mental Philosophy a Natural Science.-The science of mind, indeed, deserves in one aspect to be ranked among the natural sciences. It is a science resting on experience observation, and induction-a science of facts, phenomena and laws which regulate the same That which is specifically its object of investigation—the human mind—is strictly a part, and most important part of nature, unless we exclude man himself from the world to which he belongs, and of which he is lord. Possibility of such a Science.-The possibility of the science of the human mind has been denied by some; but without good reason. If we can observe and classify the phenomena of nature, in her varied forms, animate and inanimate, and ascertain in this way the laws to which she is subject; if it is possible thus to construct a science of plants, of animals, of the elements that compose the substance of the earth, of the strata that lie arranged beneath its surface, of the forces and agencies that at any time, recent or remote, have been at work to produce the changes which have taken place upon and within our globe-nay, more, if leaving our own planet we may, by careful observation of the heavenly bodies, learn their places, movements, distances, estimate their magnitude and density, measure their speed, and thus construct a science of the stars, surely the phenomena of our own minds, the data of our own consciousness, must be at least equally within our reach, and equally capable of observation, classification, and scientific statement. If we can observe the habits of animals and plants, we can observe also the habits of men, and the phenomena of human thought and passion. If the careful induction of general truths and principles from observed facts form the basis and method of true science in the one case, so in the other. Science of Matter and of Mind analogous.-The science of matter, and the science of mind agree perfectly in this, that all we know of either is simply the phenomena which they exhibit. We know not matter as it is in itself, but only as it affects our senses. We perceive certain qualities or properties of it, and these we embody in our definition, and beyond these we say nothing, because we know nothing Equally relative is our knowledge of mind. What it is in itself we know not, but only its phenomena as presented to our observation and consciousness. It thinks and feels, it perceives, remembers, reasons, it loves, hates, desires, determines; these exercises are matter of experience and observation; they constitute our knowledge and our definition of mind, and beyond we cannot go. Modes and Sources of Information the same in both. This being the case, it is evident that both our sources of information, and our mode of investigation, must be essentially the same in the two departments of science. In either case our knowledge must be limited to phenomena merely, and these must be learned by observation and experience. A careful induction of particulars will place us in possession of general principles, or laws, and these, correctly ascertained and stated, will constitute our science, whether of matter or mind. They differ in one Respect. In one respect, indeed, our means of information with regard to the two branches of science differ. While both matter and mind can be known only by the observation of the phenomena which they present, in mental science the field of such observation lies in great part within ourselves-the phenomena are those of our own present or former consciousness-the mind is at once both the observer and the object observed. This circumstance, which at first seems to present a difficulty, is in reality a great advantage which this science possesses over all others. Apparent Difficulty.-The difficulty which it seems to present is this: How can the eye perceive itself? How can the mind, as employed, for example, in remembering, or judging, or willing, inspect its own operations, since the moment its attention is turned to itself it is no longer engaged in that operation which it seeks to inspect — is no longer remembering, or judging, or willing, but is employed only in self-observation? We admit that the mind, in the very instant of its exercising any given faculty, cannot make itself, as thus engaged, the object of attention. But the operations of the mind, as given in consciousness, at any moment, may be retained or replaced by memory the next moment, and as thus replaced and attested, may stand be |