ing the Syllogism from all disgrace-Lengthened quotations-His OF THE POPULAR FORMS OF ARGUMENT. Misapprehension of Locke, Campbell, Lord Kames, and other distin- guished authors, on this point-Popular forms of Reasoning vari- ously classified-Regular and Irregular Arguments-Direct and Indirect — Argumentum ad hominem; ex concesso; a fortiori; ad judicium; ad verecundiam; ad populum; ad ignorantiam -Reductio ad absurdum-A priori; a posteriori-Synthetic; Analytic-Moral Reasoning-Demonstrative Reasoning-These all to be retained and employed-Logic unfolds the principle on which they rest, and tests their validity-Importance of analysing OF THE NATURE AND LAWS OF EVIDENCE. All Reasoning presupposes data-Belief must rest on some ground or reason-This called Evidence-Acquaintance with the Laws of Evidence necessary-Classification of the Sources of Evidence- Simplest division into Intuitive and Deductive Evidence-Mathe- matical and Physical Axioms-Evidence of the Senses-Conscious- ness- -Common Sense-Memory-Characteristics of Intuitive Evi- dence-The Nature and Properties of Demonstrative and Moral OF THE CAUSES OF ERROR IN JUDGING AND REASONING. Numerous hindrances in searching after truth-An error, what, and fruitful source of error-Classification of Prejudices-Lord Bacon's The province of Grammar and Rhetoric-Grammar the introduction to Logical Studies-Popular Grammar-Philosophical Grammar --Rhetoric an extension of Logic-The office of the Logician and of the Rhetorician stated and illustrated-Method not a Logical instrument-Importance of Method-Analytic Method; Method of Invention-Synthetic Method; Method of Instruction-Themes -Disputations-These properly belong to Rhetoric, Pp. 184-187 LOGIC. INTRODUCTION. No branch of study has suffered so much from perversion and neglect as Logic. To form just views of its nature and object, and to rectify the mistakes that prevail respecting it, is therefore the first thing that demands attention. 66 The term Logic is derived from a Greek word, (λoyos,) which, among other meanings, signifies reason. This term, however, is ambiguous. It may denote either" Reason," comprising all those intellectual powers of man on which his claim to rationality is founded ;-or it may mean a reason," in the sense of an argument, or proof, to establish a point at issue ;- -or it may signify "Reasoning," that process by which we draw an inference from facts or opinions previously known and admitted. Hence it has happened that the name Logic, at different times, has assumed a signification more or less extended, according to the views of the different writers by whom it is employed. Some have used it as including all the operations of the Human Intellect, as if it were intended to teach us "the right use of Reason;" while by others it is restricted to the apparently simple but important act of drawing a conclusion from given premises; or of deducting from truths already admitted, another truth, in which it is thus shewn to be involved. This diversity in the application of the term has, as a matter of course, given rise to much confusion and controversy. Not only the name, but the nature and object of the study have A been misunderstood and misrepresented; and very serious mistakes, and much mischief, have been the consequence. Writers on Logic, not having clearly defined its peculiar province, or discriminated it from other departments of knowledge, have extended its limits beyond all reasonable bounds; and many, perceiving its utter inability to accomplish what it's fond votaries promise, have therefore consigned it to contempt or oblivion. We beg leave to state distinctly at the outset, that in this treatise we bring forward no such vain, though highsounding, pretensions. We profess not to lay down rules for thinking on all topics with precision and accuracy; or for forming a correct judgment on all occasions, and on all subjects; or for opening up a royal road to the acquisition of all truth. Such promises can only lead to disappointment. We restrict the name and the province of Logic to that operation of the mind by which we infer one truth from certain other truths; or by which we proceed, from certain statements previously admitted, to another statement resulting from them, or on which it is founded. The proper business of Logic is simply Reasoning, or Argumentation. By Reasoning, in the sense in which it is here used, we understand all the elements of which it is composed. In every act of reasoning a conclusion is drawn from premises; these premises are made up of propositions; and propositions are formed of terms. Each of these is a constituent part of an Argument; hence they all fall within the province of Logic. In reference to the terms of which propositions consist, and even to the propositions themselves, it is scarcely necessary to observe that they do not constitute reasoning. For instance, "man," "Buonaparte," "ambitious," "miserable," are terms. Again, "Buonaparte was a miserable man; "Buonaparte was an ambitious man;" these are propositions. But not one of these contains an act of reasoning. Neither the terms themselves, nor the collocation of the terms in simple propositions, however modified or arranged, can be so designated. There must be a certain connexion existing and expressed between the propositions that form an argument. There must be an act of the mind comparing these propositions; evolving what they virtually contain; and drawing an inference or conclusion from them such as they warrant. Every argument, therefore, consists of two parts :-that which is proved, and that by means of which the proof is established. It is of no consequence to the validity of an act of reasoning which of these parts is first stated. Sometimes that which is to be proved is laid down first, and then the reason or proof follows. At other times the proof is first given, and then the inference is drawn. In all cases, however, the conclusion, whether stated first or last, may be easily known by those connecting particles, "therefore," "consequently," "since," "because," or their equivalents; and where these conjunctions cannot with propriety be used, whatever the number, or order, or meaning of the terms and propositions may be, there is no Argument. It is a mistake to suppose that Reasoning, or the use of Arguments, is confined only or chiefly to disputation. Mathematicians are constantly engaged in reasoning; but they establish their propositions by proofs so exact as to preclude even the possibility of controversy. We are all occupied, more or less, in giving Reasons for our opinions; in drawing Conclusions from what we learn or know; in supporting these conclusions by some kind of Proof; and in answering the Objections that may be brought against us. These forms of expression, and others of a similar import, have all a reference to Reasoning; and it is the province of Logic to teach us how to proceed so as to reason conclusively, and to express ourselves, in this important work, with clearness and accuracy. It is, however, the reasoning process, the principles on which it is founded, and the laws by which it is regulated, that form the proper object of Logic. To analyse the mental powers employed in reasoning, and to investigate their various phenomena, belong to the Metaphysician. It is only so far as they are subject to the laws of Reasoning that they claim the attention of the Logician. It is his office to analyse the principles on which argumentation is founded, and to lay down rules to guide and guard us in this matter of constant, universal, and primary importance. Logic is chiefly occupied with the laws of thought, restricted as above. But as language is the vehicle of thought, it must also necessarily, in some degree, take cognisance of the medium of communication. This, however, may be viewed as only a secondary object. It |