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INSTITUTES OF LOGIC.

PART I.

LOGICAL PSYCHOLOGY. HISTORICAL NOTICES. THE LAWS OF THOUGHT.

CHAPTER I.

INTRODUCTORY—LOGIC: ITS NATURE; RELATION TO PSYCHOLOGY AND METAPHYSICS.

§ 1. The central conception of Intellectual Philosophy is that implied in the term Truth. This, with the cognate term Certainty, indicates the aim of intellectual effort as animated by the natural desire of knowing. Knowing has various ends or degrees. We may seek simply to know ordinary matters of fact, to acquire science, to go back on the first principles and laws of knowledge itself. We may rest in the individual fact, we may generalise and classify, wo may speculate on what is ultimate in knowledge. In each case, however, what we seek is Truth and Certainty.

§ 2. Speaking generally, Truth is the harmony or conformity between fact or reality and our knowledge of it. Fact may mean either an individual thing, quality, object, or a class or law, generalised or necessary, of matter or mind. Conformity always implies a certain plurality or dualism, for of

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the same to the same there is no conformity, only identity. Certainty is the consciousness of truth,—conviction, as resting on evidence, immediate or mediate.

§ 3. In ordinary knowledge, in history, in science, we aim at truths rather than Truth. Each fact, event, each law of nature, adequately known is in the mind a truth; and a body of these laws, co-ordinated, classified, systematised, is a science in a more or less perfect form. We may ask the question, What are the truths of history or of science, and seek to find them. This would be historical or scientific knowledge. But we may also ask the question, What is Truth?—truth itself— the essence or inner being of it, so to speak. What have truths in common that we call them truths? Can we get the mark, criterion, test of truth itself, or of this or that truth? How far can we go in assuring ourselves that what we believe to be true is true? And what is the meaning, or what are the meanings, of saying that there is truth, or that a given proposition is true? This is the question, or set of questions, with which Intellectual Philosophy is concerned. It occupies itself with the nature, conditions, criteria of truth.

§ 4. If we take this question of what is truth, or true knowledge, in its widest generality, it is obvious that we must raise the questions as to the ultimate ground and nature of knowledge and certainty. Supposing that we know at all, or believe that we know, as a matter of fact, this knowledge must have a ground or beginning, for us at least. "If it is not possible," says Aristotle, " to know first things, neither can we know, either absolutely or properly, things which result from these, but by hypothesis, if these exist . All science is not demonstrative, but the science of the immediate is indemonstrable. . . . Some time or other we must stop at immediate (propositions)."1 And we thus are confronted with the question as to the first principle or principles of knowledge. And as true knowledge is real knowledge, or knowledge of what is, we are met by the correlative question as to what we know of the real,—what reality is, and what are its kinds. A science of knowledge, therefore, in its widest sCope would be a science of first principles, and of being as it stands in knowr ledge. This would lead to the discussion of the difference between phenomenal reality or knowledge, so called, and 1 Aristotle, An. Post., 1. i. c. 8, 4.

substantial reality,—what is the nature and what the limits, if any, of our experience.

§ 5. These questions touching the nature of reality, the nature of the various objects of our knowledge, have been properly assigned to that branch of Philosophy known as Metaphysics or Ontology. We may confine our inquiries into the laws and conditions of our knowledge of the contents of experience, without, for example, considering whether these contents have a simply subjective reality, are mere conscious impressions, or, as known, are something more and other than this. We may further carry on this inquiry without considering the question as to the nature of ultimate or primary reality. It is sufficient for this end that we know, and know what we call objects, whatever these be in their essence or origin. That we are conscious, that we have experience at all, is a sufficient basis for certain questions regarding the conditions and possibility of this experience.

§ 6. The discussion even of these ultimate questions may presuppose that there are certain laws or features of knowledge,— universal and essential in knowledge, — and thus there may be a science which precedes even such discussion, as regulating human intelligence and thought itself, or the very conception of an object of knowledge itself. And if there be such a science, it will have a place of its own, and be so far independent of and above all other sciences. It would profess to lay down the conditions of the knowable, and especially of the thinkable,—that is, to state certain laws or principles without which there is no object of knowledge or thought for us at all. As such, it will be found to embrace certain conditions of knowledge and thought, apart from the fulfilment of which the ideal existence of an object, or an object in knowledge, is not possible. This impossibility may arise from two sides: first, from the side of knowledge. Here there are certain conditions to be fulfilled ere an object can be an object of knowledge or thought at all. These are the conditions of Identity and Non-contradiction, and they are inseparable from the nature of the act of knowing. Certain conditions lie on the side of the object as existing, and these are given in the object or with the object. They form the essential elements or relations of the object. These are the relations of Subject and Object,—Qualitative, as Substance

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