LECTURE IV. INTRODUCTION. LOGIC-III. ITS DIVISIONS-PURE AND MODIFIED. tion. IV. IN my last Lecture, after terminating the considera- LECT. tion of the second introductory question, touching the Utilities of Logic, I proceeded to the third introduc- Recapitulatory question,-What are the Divisions of Logic? and stated to you the two most general classifications of this science. Of these, the first is the division of Logic into Objective and Subjective, or Systematic and Habitual; the second is its division into General and Special, or Abstract and Concrete. To speak only of the latter,-Abstract or General Logic is logic viewed as treating of the formal laws of thought, without respect to any particular matter. Concrete or Special Logic is logic viewed as treating of these laws in relation to a certain matter, and in subordination to the end of some determinate science. The former of these is one, and belongs alone to philosophy, that is, to the science of the universal principles of knowledge; the latter is as manifold as the sciences to which it is subservient, and of which it, in fact, constitutes a part,-viz. their Methodology. This division of logic is given, but in different terms, by the Greek Aristotelians and by the Latin schoolmen. IV. LECT. The Greek division does not remount to Aristotle, but it is found in his earliest expositor, Alexander of Aphrodisias, and he was probably not the first by whom it was enounced. It is into διαλεκτικὴ χωρίς πрауμáτшν, Logica rebus avulsa, that is, Logic merely formal, Logic apart from things, in other words, abstract from all particular matter; and SiaλEKTIKỲ Ev χρήσει καὶ γυμνασίᾳ πραγμάτων, Logica rebus appli cata, that is, Logic as used and exercised upon things, in other words, as applied to certain special objects. The division of Logica Logica taken by some mo dern authors. This distinction of Logic by the Greek Aristotelians seems altogether unknown to modern logicians. The division of Logic by the scholastic Aristotelians is the same with the preceding, but the terms in which it is expressed are less precise and unambiguous. This division is into the Logica docens and Logica utens. The Logica docens is explained as logic considered as an abstract theory,—as a preceptive system of rules, -"quæ tradit præcepta ;"-the Logica utens, as logic considered as a concrete practice, as an application of these rules to use,-"quæ utitur præceptis."" This scholastic division of Logic into docens and docens, and utens has, I see, been noticed by some of the more utens, mis- modern authors, but it has been altogether mistaken, which it would not have been had these authors been aware of the meaning in which the terms were employed, and had they not been ignorant of the more explicit expression of it by the Greeks. Thus the terms docens and utens are employed by Wolf to mark a distinction not the same as that which they designate in the scholastic logic, and as the Wolfian distinction will not stand the test of criticism, the terms themselves have been repudiated by those who a Smiglecii Logica, Disp. ii. q. vi. For scholastic authorities, see Aquinas, In IV. Metaph., lect. iv.; Scotus, IV. were not aware, that there was an older and a more LECT. valid division which they alone properly expressed." Wolf makes the Logica docens, the mere knowledge of the rules the Logica utens, the habit or dexterity of applying them. This distinction of General and Special logic, Wolf and the Wolfian logicians, likewise, denote by that of Theoretical and Practical Logic. These terms are in themselves by no means a bad expression of the distinction, but those by whom they were employed, unfortunately did not limit their Practical Logic to what I have defined as Special, for under Practical they included not only Special, but likewise Modified Logic, of which we are now to speak. Having explained, then, this primary division of Logic into General and Special, and stated that General Logic, as alone a branch of philosophy, is alone the object of our consideration; I proceed to give the division of General Logic into two great species or rather parts,—viz. into Pure or Abstract and Modified or Concrete. General ed into Pure fied. ¶ VIII. In the third place, considered by reference Par. VIII. to the circumstances under which it can come into Logic,dividexercise by us, Logic,-Logic General or Abstract, and Modiis divided into Pure and Modified ;-a division, however, which is perhaps rather the distribution of a science into its parts than of a genus into its species. Pure Logic considers the laws of thought proper, as contained a priori in the nature of pure intelligence itself. Modified Logic, a [As Krug] [see his Logik, § 11, p. 30. p. 12; Sauter, Positiones Logicæ, P. Compare Kant, Logik, Einleitung, ii.— I. and II., 1778; Instit. Log., P. ED.] B Wolf, Philosophia Rationalis, §§ 8, 9, 10, 12.-ED. [Cf. Stattler, Sauter, and Mako], [Stattler, Logica, § 18, I. and II., 1799; Paulus Mako de LECT. IV. Pure Logic. again, exhibits these laws as modified in their actual applications by certain general circumstances external and internal, contingent in themselves, but by which human thought is always more or less influenced in its manifestations." Pure Logic considers Thought Proper simply and in itself, and apart from the various circumstances by which it may be affected in its actual application. Human thought, it is evident, is not exerted except by men and individual men. By men, thought is not exerted out of connection with the other constituents of their intellectual and moral character, and, in each individual, this character is variously modified by various contingent conditions of different original genius, and of different circumstances contributing to Modified develop different faculties and habits. Now there may be conceived a science, which considers thought not merely as determined by its necessary and universal laws, but as contingently affected by the empirical conditions under which thought is actually exerted;which shows what these conditions are, how they impede, and, in general, modify, the act of thinking, and how, in fine, their influence may be counteracted. Nomencla- This science is Modified or Concrete Logic. What I Modified have called Modified Logic is identical with what Kant and other philosophers have denominated Applied Logic. (Angewandte Logik, Logica applicata.)ẞ Logic. ture of Logic. a For distinction of reason in abstracto and reason in concreto, grounding the distinction of an Abstract (or Pure), and a Concrete (or Modified) Logic, see Boyle's Works, iv. p. 164. See also Lambert [Neues Organon, Dianoiologie, i.-ED.], § 444, who says that the sciences in general are only applied logics. Cf. Ploucquet, p. 236 [Sammlung der Schriften welche den Logischen Calcul Herrn Prof. Ploucquets betreffen, Tübingen, 1773.-ED.] B Kant, Logik, Einleitung ii.; Hoffbauer, Anfangsgründe der Logik, §§ 17, 406; Krug, Logik, Einleitung, § 11; Fries, System der Logik, § 2.—ED. IV. The term Logic. This expression I think improper. For the term LECT perly em |