forms of language, so that the parts of speech, whether simple or compounded, are made to act differently and distinctly in the process of coming to a conclusion from premises, is an art quite apart from the Logic treated of in these pages. The former is the art of reasoning with words, so as to keep the things signified as much as possible absent from the understanding: the latter is the art of reasoning by means of words so used as to keep the things signified ever present to the understanding, in order that our conclusions may be, not from the words, but from the things they signify. Now with regard to this logic, which is the logic existing in the common daily use of language, the grammatical character of a word, or the peculiar form of a phrase or sentence, is unessential to the validity of its acts. It is, for instance, of no moment in our logic, whether we say, Man, or Reasoning man, or Man reasons, or Man is a reasoning creature, the thing meant being in each the same, and the whole of the words in the last example forming one expression for the one meaning expressed by the first. True it is that we are called upon, by the form of the first, and of the second expression, to esteem the expression only an instrument of meaning to be developed, and not as meaning yet developed; while, with regard to the last two examples, we are at liberty either to rest in the development so far made, or expect it to proceed further; and in this way Logic accepts the ministry of Grammar: but the differences are unessential in logic, and belong, properly, to the other department of learning. In our logic, again, it is of no moment whether we say, Every man is liable to error, or, No man is free from the liability to error, since each proposition, as one expression for one meaning, stands for the same meaning; and since each resolves, primarily, into two parts, namely the former proposition into Every man, and, Is liable to error; the latter, into, No man, and, Is free from the liability to error, out of which two parts, in the respective instances, the same one meaning springs. When therefore, the former is called an affirmative, and the latter a negative proposition, we leave the distinction to grammar, and consider that logic is in no way concerned with it, though in Rhetoric there will generally be a ground of preference for the one or the other. In our logic, once more, it is of no moment whether we say, Kings, like other men, are mortal, or If kings are men, they are mortal; whether we say, If the world is a sphere, we must be able to reach the same point, by moving from it in any one direction; or The world being a sphere, we must be able, &c. We may admit the one form in each of these instances to be called a categorical proposition, and the other a hypothetical or conditional one: we may also admit, on rhetorical grounds, sometimes the one, sometimes the other, to be preferable: but we do not admit that Logic, in its own strict province, has any concern with such differences, either in propositions, or in the syllogisms which may be developed from them. 40. There is, however, one description of syllogism, whose difference from others our logic acknowledges, because it is not a mere difference in form of expression, but a peculiarity in the character of the knowledge developed. The syllogism referred to, is called the DILEM'MA; a form of expression never justly possible but when the knowledge to be developed includes something true and something not true, while it does not include which is which: for instance, the knowledge or datum, that The blessed in heaven will be fully content, either because they will have no desires, or because their desires will be completely gratified: the knowledge or datum, that Eschines joined in the public rejoicings, in which case he is inconsistent; or did not join in them, in which case he is unpatriotic: the knowledge or datum, that A certain man spoke irreverently of scripture in jest, in which case he is not wise; or in earnest, in which case he is not good. These, unfolded into syllogisms, will be examples of the Dilemma; as, "If the blessed in heaven have no desires, they will be fully content; so they will if their desires are completely gratified; But either they will have no desires, or have them completely gratified: Therefore they will be fully content." "If Æschines joined in the public rejoicings, he is inconsistent; if he did not, he is unpatriotic; But he either joined or not: Therefore he is either inconsistent or unpatriotic." "If this man were wise, he would not speak irreverently of scripture in jest; and if he were good, he would not do so in earnest: But he does it either in jest, or in earnest : Therefore he is either not wise, or not good." The manner of reasoning called Reductio ad absurdum, (bringing to an absurdity,) may be mentioned with the dilemma, as requiring, like it, a double supposition; the difference being that it completely establishes one of them; as, "This road to our house is either straight or crooked. I affirm it to be straight, but I have no direct proof: say, then, that it is crooked. But it is of the same length, and extends between an equal distance, with one which we know to be straight. Thus we have two lines of the same length, and extending between an equal distance, the one by admission straight, the other by supposition crooked; which supposition is absurd. Therefore the line or road in question is not crooked; that is, it is straight. 41. An EPICHIRE'MA is a syllogism with arguments or proofs appended to one or both of the premises. Let the following syllogism be the foundation of an epichirema : Datum." An event that has always followed an act, will continue to follow it when circumstances are the same. Argument." Death has always quickly followed the drinking of this juice. Conclusion. Therefore, the circumstances continuing the same, death will, in this instance, quickly follow the act of having drunk of this juice.' The following further development will give to this syllogism the name Epichirema: Datum." An event that has always followed an act, will continue to follow it when circumstances are the same. This is not a necessary truth, but the persuasion of habitual experience, and we acknowledge its certainty by calculating, without hesitation or doubt, on issues that have often been tried. Argument." Now the drinking of this juice has always been quickly followed by death; as I can affirm from instances that have come under my own observation; from many more that have been reported to me by friends; and from innumerable others which past recorded experience bears witness to. Conclusion." Therefore, unless something can instantly be done to change the circumstances in the present case, death will quickly follow the act that has been committed." In this laborious way does Logic, if left entirely to its own mode, develop knowledge-Logic which is without passion, -without impulse to action. Rhetoric would be much more brief notwithstanding her repetitions," He'll die! he'll die! he has drunk poison! Oh! for an antidote! Virtually, we here have the whole of the previous argument, with emotion, and urgency to action, superadded. PRACTICAL DIRECTIONS CONTINUED: EXERCISES SUGGESTED FOR IMPROVEMENT IN LOGIC. 42. There can be no proper practice of Logic which is different in principle from that which directs the ordinary use of language. In the previous pages we have been employed in ascertaining what that principle is; and now that we know it, we have to act upon it as before, but with the caution which theoretical knowledge confers. It is true that the ordinary use of language aims at rhetorical effect as well as logical precision; in other words it is meant to influence others, as well as to develop the knowledge in the reasoner's mind. But in practice it is not wise, nor would it be easy, to separate Logic from Rhetoric by any very rigid line: for Logic is the proper ground of Rhetoric, and the practice of Rhetoric includes or ought to include Logic. In following such exercises as are hereafter suggested, the learner is therefore only cautioned against any style which dispenses with a patient and laborious employment of thought but provided he fulfils his duty in the clear development of his own knowledge, he needs not be the less satisfied, if his language has a correspondent effect upon other understandings. 43. Improvement in Logic is best promoted by the writing of what are called THEMES The word theme properly means the subject of a discourse but the discourse itself, if merely an exercise, is also called a theme. We begin with a title, which title may be a single grammatical noun, or a logical noun, or a proposition.† 44. The title or subject of a theme being a mere grammatical noun, will be the name of a thing real, or ideal, or metaphysical; while the name itself will be proper, common, * Compare Section 1 of the present Chapter, p. 140. or abstract. Thus Solomon, Socrates, Alexander, King Alfred, Homer, Virgil, Shakspeare, Milton, Aristotle, Bacon; London, Rome, Paris; Thames, the Rhine; Vesuvius, the Alps; are proper names of real persons and things: Ceres, Bacchus, Queen Mab, Lilliput, Brobdignad; are proper names of ideal persons or things: Animals, Vegetables, Minerals; Man, Beast, Bird, Fish, Insect; Tree, Shrub, Herb; Earth, Stone, Metal; Fire, Air, Earth, Water; are common names of real things: Fairies, Ghosts, Fauns, Nymphs; are common names of ideal things: Virtues, Vices, Qualities, Attributes; are common names of things metaphysical. Faith, Hope, Charity; Prudence, Justice, Temperance, Fortitude; are names abstract of things metaphysical. And any one of these becomes the title of a theme by putting the word On before it. 45. Among the previous classes of names or subjects, that of most frequent choice or occurrence will be the last,—a thing metaphysical under a name abstract: of which the following are given as further instances, with hints subjoined to assist the learner in developing his knowledge. Оп On Conversation. On Writing. On Reading. On Travelling. On History. On Building or Architecture. Sculpture. On Painting. On Music. On Poetry. These are things exercised, or done, or known, and imply persons who exercise or know them. Hence they are things metaphysical, and the cautionary principles † must be kept in mind. The generic name will be, an ability or practice, an art, a science: an art may be further developed by the distinction mechanic; or fine,-(ornamental;) and the specific nature or more particular description will complete the first point. Then may come some one, or more, or all of the following points: the improvement or the use derived or derivable: the pleasure derived or derivable; the abuse or omission, and consequent disadvantage or mischief. In some instances, the progress of the art or science from early times to the present may be glanced at. Such are the points which may be taken in treating the foregoing subjects. *Ordinary and not scientific knowledge, is aimed at in suggesting these titles. In Chapter II. Sections 15, 16 at pages 114, 115; and Sections 20, 21 at page 118. |