UNIVER

CA

LOGIC,

OR

THE THEORY OF THOUGHT.

PART FIRST.-INTRODUCTORY.

I. DEFINITION OF LOGIC.

§ 1. Logic is the science of the necessary forms of thought. The word "Logic" is derived from the Greek Moyen, an adjective qualifying ἐπιστήμη (science) or πραγμητεία (matter of study) understood. The meaning of Aoyun and of its original, λóyoç, is ambiguous. The latter is equivalent to both the ratio and the oratio of the Latins, to thought and to speech. This ambiguity passed into the derivative, and has affected the views of many logicians as to the objectmatter of the science, some holding that it treats of words or language rather than of thought.'

Aristotle did not designate by the term λoyun the science whose doctrine he first fully developed. The terms Analytic, Apodeictic,

1 See Hamilton's Logic, p. 3. It may be well to note at the outset that logicians are divided into three schools, according as they hold words, things, or conceptions to be the subject of Logic; and these are entitled, respectively, the Verbal, the Phenomenal, and the Conceptional Schools. The first is represented by many scholastics, by Hobbes, Whately, and De Morgan. The second numbers Bacon, Helvetius, Comte, J. S. Mill, and Bain among its chief expositors. At the head of the third is Kant, followed by Krug, Esser, and the recent German logicians generally, and by Hamilton and Mansel with their train of Scotch and English pupils; to whom may be added most French writers, following Arnauld. The present treatise takes the Kantian, or conceptualist, view. Logic treats of thought. But as thought is always about things, and is expressed in words, Logic cannot proceed in entire disregard of these, but should constantly keep them subordinate. See Cretiens's Logical Method, ch. v. Oxford, 1848.