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are most fully developed; the civilized state is that in which all man's faculties are most fully developed: therefore, to discover whether man has any moral sense, he should be viewed in a civilized state.
104. Revenge, Robbery, Adultery, Infanticide, fc. have been countenanced by public opinion in several countries : all the crimes we know of are Revenge, Robbery, Adultery, Infanticide, fc.: therefore, all the crimes we know of have been countenanced by public opinion in several countries.
105. No soldiers should be brought into the field who are not well qualified to perform their part. None but veterans are well qualified to perform their part. None but veterans should be brought into the field.
106. A monopoly of the sugar-refining business is beneficial to sugar-refiners: and of the corn-trade to corngrowers : and of the silk-manufacture to silk-weavers, &c. &c.; and thus each class of men are benefited by some restrictions. Now all these classes of men make
the whole community: therefore a system of restrictions is beneficial to the community. (See Chap. iii. § 11.]
107. There are two kinds of things which we ought not to fret about: what we can help, and what we cannot. [To be stated as a Dilemma.]
PRAXIS OF LOGICAL ANALYSIS.
Some have expressed much contempt for the mode in which Logic is usually taught, and in which students are examined in it, as comprising no more than a mere enumeration of technical rules, and perhaps an application of them to the simplest examples, exhibited in a form already syllogistic, or nearly so. That such a description, if intended to be universal, is not correct, I am perfectly certain; though, hitherto, the indiscriminate requisition of Logic from all candidates for a Degree, has confined both lectures and examinations, in a greater degree than is desirable, to this elementary character. But the student who wishes to acquire, and to show that he has acquired, not only the elementary rules, but a facility of applying them in practice, should proceed from the study of such examples as the foregoing, to exercise himself in analysing logically, according to the rules here given, and somewhat in the manner of the subjoined specimen, some of Euclid's demonstrations,—various portions of Aristotle's Works,--the opening of Warburton's “ Divine Legation,” (which exhibits the arguments in a form very nearly syllogistic) several parts of Chillingworth's Defence of Protestantism,the concluding part of Paley's Horæ Paulinæ,-Leslie's Method with the Deists,—various portions of A. Smith's Wealth of Nations, and other argumentative Works on the most dissimilar subjects. The latter part of $ 1.
Chap. V. of the Dissertation on the Province of Reasoning, will furnish a convenient subject of a short analysis.
A student who should prepare himself, in this manner, in one or more such books, and present himself for this kind of examination in them, would furnish a good test for ascertaining his proficiency in practical Logic.
As the rules of Logic apply to arguments only after they have been exhibited at full length in the bare elementary form, it may be useful to subjoin some remarks on the mode of analysing and reducing to that form, any train of argument that may be presented to us : since this must in general be the first step taken in an attempt to apply logical rules. *
First then, of whatever length the reasoning may be, whether treatise, chapter, or paragraph, begin with the concluding assertion ; — not necessarily the last sentence expressed, but the last point established ;—and this whether it be formally enunciated, or left to be understood. Then, tracing the reasoning backwards, observe on what ground that assertion is made. The assertion will be your Conclusion ; the ground on which it rests, your Premises. The whole Syllogism thus obtained may be tried by the rules of Logic.
If no incorrectness appear in this syllogism, proceed to take the premises separately, and pursue with each the same plan as with the conclusion you first stated. A premiss must have been used as such, either because it required no proof, or because it had been proved. If it have not been proved, consider whether it be so self-evident as to have needed no proof. If it have been proved, you must regard
* These directions are, in substance, and nearly, in words, extracted from the Preface to Hinds’s abridged Introduction to Logic.
it as a conclusion derived from other assertions which are premises to it: so that the process with which you set out will be repeated ; viz. to observe on what grounds the assertion rests, to state these as premises, and to apply the proper rules to the syllogism thus obtained. Having satisfied yourself of the correctness of this, proceed, as before, to state its premises, if needful, as conclusions derived from other assertions. And thus the analysis will go on (if the whole chain of argument be correct) till you arrive at the premises with which the whole commences; which of course should be assertions requiring no proof, or, if the chain be any where faulty, the analysis will proceed till you come to some proposition, either assumed as self-evident, though requiring proof, or incorrectly deduced from other assertions.*
It will often happen that the same assertion will have been proved by many different arguments; and then, the inquiry into the truth of the premises will branch out accordingly. In mathematical or other demonstrative rea
Many students probably will find it a very clear and convenient mode of exhibiting the logical analysis of a course of argument, to draw it out in the form of a Tree, or Logical Division; thus,
Z is X proved by
soning, this will of course never take place, since absolute certainty admits of no increase: and if, as is often the case, the same truth admits of several different demonstrations, we select the simplest and clearest, and discard the rest. But in probable reasoning there is often a Cumulation of arguments, each proving the same conclusion ; i. e. each proving it to be probable. In such cases therefore you will have first to try each argument separately; and should each of them establish the conclusion as in some degree probable, you will then have to calculate the aggregate probability
In this calculation Logic only so far assists as it enables us to place the several items of probability in the most convenient form. As the degree of probability of each proposition that is assumed, is a point to be determined by the reasoner's own sagacity and experience as to the matter in hand, so, the degree of probability of each conclusion, (given, that of each of its premises,) * and also the collective probability resulting from several different arguments all tending to the same conclusion, is an arithmetical question. But the assistance afforded by logical rules in clearly stating the several items so as to prepare the way for the other operations, will not be thought lightly of by any who have observed the confusion of thought and the fallacy, which have often been introduced through the want of such a statement.
Example of Analysis applied to the first part of Paley's
Evidences. The ultimate Conclusion, that “ The Christian Religion came from God” is made to rest (as far as " the direct historical evidence” is concerned) on these two premises;
* See Fallacies, § 14, near the end.