4. The foundation of all affirmative conclusions is laid in this general truth, that, so far as two ideas agree with any third idea, they agree between themselves. The character of Creator agrees with God, and worship agrees with a Creator, therefore worship agrees with God.

5. The foundation of all negative conclusions is this, that, when one of the two proposed ideas agrees with a third idea, and the other disagrees with it, they must disagree as far with each other; as, for example," No sinners are happy; and if angels are happy, then angels are not sinners." Thus appears the strict notion of a syllogism.

9. A syllogism consists of three propositions, so disposed, that the last is necessarily inferred from those which precede it. As,

Syllogism.

The Premises.

Conclusion.

Major. Our Creator must be worshipped;

Minor. God is our Creator;

Therefore, God must be worshipped.

7. The first proposition, "Our Creator must be worshipped," is called the major; the second proposition, "God is our Creator," is called the minor proposition, and both of them are called the Premises. The third term is called the Conclusion.

8. The subject and predicate of the conclusion are called the extremes; that with which they are compared, is called the middle term or argument. Of the extremes, the predicate, as it is always taken in its full extent or comprehension, is called the major, and the subject the minor term. That proposition which contains the predicate of the conclusion, connected with the middle term, is usually called the major proposition, whereas, the minor proposition connects the middle term with the subject of the conclusion, and is sometimes called the assumption.

9. When the syllogism is regularly composed, the major proposition is generally placed the first; the minor, the second; and the conclusion, the last. Thus, in the preceding syllogism, God, worshipped, and Creator, are the three terms of the syllogism. God and worshipped are the extremes; God, the minor; worshipped, the major; and Creator, the middle term.

10. The other kinds of argument are the Epichirema, Dilemma, Sorites, and Enthymeme.

1. The Epichirema is an argument which contains the proof of the major or the minor, or both, before it draws a conclusion. This is frequently used in writing, in public speeches, and in common conversation, in order that each part of the discourse may be confirmed, and put out of doubt, as it proceeds towards the conclusion which was chiefly designed. Thus, the oration of Cicero for Milo, comes under this figure. "It is lawful for a person to kill those who lie in wait to kill him, as is allowed by the law of nature, and the practice of mankind. Now, Clodius laid in wait for Milo with that intention, as appears from his guard of soldiers and his travelling armed; therefore, it was lawful for Milo to kill Clodius." The first proposition the orator proves from natural equity, from the custom of nations, from examples;-the second he proves by the arms, guards, &c., which Clodius had provided. And these two being proved, the conclusion is irresistible.

2. The Dilemma is an argument which, presuming that one of two different suppositions must be true, proves that one of them is false, and concludes that the other, therefore, must be true. Thus, "If God did not create the world perfect in its kind, it must have been from want either of inclination or of power. But it could not have been from want either of inclination or of power;-Therefore, he created the world perfect in its kind." For this figure to be correct, two things are required, 1st, The full enumeration of all the particulars of a subject; 2nd, That it press the opponent only, and be not liable to be retorted with equal force upon the person who uses it.

3. The Sorites is an argument consisting of a series of propositions, in which the predicate of the first becomes the subject of the second, and so on, till, in the conclusion, the subject of the first is joined with the predicate of the last; thus, "All who love wisdom, will earnestly desire it;""All who earnestly desire it, will use the necessary means to obtain it;""All who use the means of obtaining it, will encounter many difficulties;" "All who encounter difficulties, must exercise patience, perseverance, and self-denial." Therefore, all who love wisdom, must exercise patience, perseverance, and self-denial.

4. The Enthymeme is an argument in which the conclusion is drawn at once from one of the premises, without the syllogistic form; as, "There is no true religion without good morals; therefore, a robber cannot be truly religious." This forms the most common kind of argument, both in conversation and in writing.

11. Evident and certain arguments are called demonstrations. A Demonstration à priori is, when the effect is proved by its necessary cause; as, "There is light, because the sun shines."

12. A Demonstration à posteriori infers the cause from its necessary effect; thus, "I infer that there has been the hand of some artificer here, because I find a curious figure."

13. Some arguments are direct, immediately proving the proposition in question; thus,

The Maker of the Universe must be a powerful Being;

the Universe exhibits innumerable proofs of the power exerted in its arrangement;

therefore, its Maker must be possessed of infinite power.

Other arguments are indirect, proving the conclusion, by proving or disproving some proposition on which it depends; thus,

If we would ascertain, "whether the moon be an opaque or a transparent body," we might reason indirectly by the following argument:-" Astronomers have shown that the moon's interposition between the sun and the earth occasions an eclipse of the sun; but, if the moon were a transparent body, her interposition would not obscure the sun's light by an eclipse, therefore, she is not transparent, but opaque."

Thus, the indirect mode of reasoning, by proving one alternative of a question, refutes the other, and shows that it is untenable.

Of indirect arguments there are three cases: Reductio ad absurdum, proves the conclusion, by demonstrating the absurdity of the contradictory proposition. Argumentum à fortiori, proves a less probable supposition upon which it depends, and, consequently, the original proposition is true, because it is more probable. Argumentum ex concesso, proves a proposition on which it was agreed to rest the original question.

Argumentum ad judicium, is an address to the reason of man. Argumentum ad fidem, an address to the faith of man. Argumentum ad ignorantiam, an address to our ignorance. Argumentum ad hominem, an address to our professed principles. Argumentum ad verecundiam, an address to our modesty. Argumentum að passiones, an address to the passions;-ad populum, to the people.

14. When an argument carries the appearance of truth with it, and yet is erroneous, it is termed a Sophism.

Of the various kind of Sophisms, the following are the principal:-1. Ignoratio Elenchi, or a Mistake of the Question, is when something is proved which has no necessary connection or consistency with the point really under discussion; and, consequently, affords no real ground for determination respecting it. Thus, if the question, "Whether excess of wine can be hurtful to him that drinks it," a person, by proving that it revives his spirits, gives a man courage, and makes him strong and active, should take it for granted, that he has proved his point, his conclusion would be wrong; for the respondent may easily show, that though wine may do all this, yet it may be, finally, injurious both to the soul and body of him that drinks it to

excess.

2. Petitio Principii, or Begging the Question, is when the very thing to be proved, is taken for granted: thus, "The human soul is extended through all the parts of the body, because it resides in every member." The latter part of this sentence is no proof of the former, but merely the same thing in other words.

3. Arguing in a Circle, is when the premises are proved by the conclusion, and the conclusion by the premises.

4. Non causa pro causâ, is assigning a false cause. Thus, "Christianity, in the primitive ages, was charged by the heathens with all the calamities that befel the Roman Empire, because the Christians renounced the heathen gods and idols."

5. Fallacia accidentis, is arguing from what is merely accidental to what is essential; thus, "Learning and printing may have been the accidental cause of sedition in a state;" "Reading the Bible has been accidentally abused to promote heresies or destructive errors;" and for these reasons they have all been pronounced evil things,

6. A dicto secundum quid, ad dictum simpliciter, is when we argue from that which is true in particular circumstances, to prove that the same thing is true absolutely, and in all circumstances; thus, Livy writes fables and improbabilities when he describes prodigies and omens; therefore, Livy's Roman History is never to be believed in any thing."

7. The reverse of this is, when we argue from a moral universality which admits of some exceptions, as if it were a natural universality which admits of no exceptions; as, if a traitor should argue from the sixth commandment, "Thou shalt not kill a man," to prove that he himself ought not to be hanged. The erroneousness of this kind of reasoning may be shown, by stating the difference between things in their absolute nature, and the same things considered with respect to particular times, places, persons, and circumstances.

8. Sophisms of Equivocation are when the argument depends upon the ambiguity of the terms; as, if we should argue thus, He that sends a book into the light, desires it to be read; he that throws a book into the fire, sends it into the light; therefore, he that throws a book into the fire, desires it to be read." This sort of fallacious reasoning is solved by showing the different senses of the words or phrases. Here, light, in the major proposition, signifies the public view of the world; in the minor, it

Z

signifies, the brightness of flame and fire; the syllogism has, therefore, four terms, or, rather, it has no middle term, and proves nothing.

15. The principles by which we must prove the truth of every argument are, that the terms employed in it must be used in precisely the same sense throughout; that the premises themselves must be just, and must afford a full justification of the conclusion. And, in applying these, sound sense and the habit of discrimination are our best guides.

4. Method.

The fourth operation of the Mind is Method, or, the Arrangement of our thoughts in such an order as may enable us not only to discover unknown truths, but also to explain and confirm those truths that are known, or to impress them in the memory. Method requires a just distribution of all the parts of a subject, and that every thing of the same kind should be placed in its appropriate situation.

In addition to what we have already advanced, it is proper here to explain the terms Analysis, Synthesis, Generalization, and Analogy.

1. When a whole subject is divided into its several parts, and we proceed regularly from generals to particulars, the method pursued is called the Analytic. An Analysis is made by observing the differences of things; in order that, by separating things that differ, we may become perfectly acquainted with each; and so with the whole. Thus, we may have a general notion of an animal, but it is only by the study of anatomy we can gain an accurate knowledge of its cartilages, bones, veins, nerves, and all its other parts. This is the analytic method, and is sometimes called the method of invention.

2. When we begin with the most simple principles, and general truths, and proceed by degrees to what is drawn from them, or compounded of them, we use the Synthetic method. Thus, the parts are united together according to their mutual connection and affinity, so as to show what kind of whole these parts will compose. In learning grammar, for instance, we first acquire the knowledge of letters; we combine them to make syllables: of syllables are composed words, and of words sentences and discourses. This is the Synthetic method, and is called also the method of instruction.

3. Generalization is that process of the mind by which we observe and examine phenomena, and, from the examination of them, derive those general laws or prin ciples agreeably to which they take place. When we arrive at the knowledge of some truth, by a close and accurate examination of every particular, under every variety of circumstance, we have employed the principle of Induction; that is, we have drawn a general inference from a number of facts or experiments.

4. There are numerous cases, however, in which experiment and induction cannot be employed. Here, analogical reasoning is often advantageous. By Analogy, the similarity of causes or general principles is inferred from the resemblance or correspondence of circumstances. And where the things compared have really a great similarity in their nature, when we have reason to think that they are subject to the same laws, there may be a considerable probability in conclusions drawn from analogy. Thus, as in the example given in page 194, we may observe a great similarity between this earth and the other planets; they all revolve round the sun, are subject to the same laws of gravitation; and, reasoning analogically, we may suppose, that as God has replenished this earth with creatures, He has done the same in other similar parts of the creation; and that, therefore, the planets, in all probability, are likewise inhabited by living creatures. But it ought to be observed, that, as this kind of reasoning can afford only probable evidence at the best, so, unless great caution be used, we are apt to be led into error by it. For, we are sometimes disposed to conceive a greater similitude between things than really exists.

255

ADVICE TO THE STUDENT,

ON THE MENTAL HABITS NECESSARY FOR THE ATTAINMENT, RETENTION, AND READY APPLICATION OF KNOWLEDGE.

In concluding this work, I have thought it advisable to present the young student with a few hints on the Mental Habits which are necessary for the Attainment, Retention, and Ready Application of Knowledge. The utility of inserting such observations in this place will, it is hoped, be so obvious, as to render it unnecessary to adduce any arguments in favour of such a mode.

I. ON THE ATTAINMENT OF KNOWLEDGE.

In treating of this subject, I shall consider first, The mental habits which obstruct; and, secondly, Those which contribute to advance the Attainment of Knowledge.

1. Mental Habits which obstruct our Progress.

1. The first great obstacle to all advancement in knowledge is, the pursuit of a multiplicity of objects at once.

When we are hurried from object to object, devoting a little time to this and a little to that, our attention is divided, our energies become enfeebled, sufficient time is not allowed for forming clear ideas upon any one subject, the impressions made upon the mind are faint, and, of course, transient; we thus become confused, and as no progress is made, no satisfaction can be derived.

In no respect, therefore, is wisdom more evinced than in knowing what things we ought to attempt, and to what extent we can go. Thus, what might be proper for one who has the disposal of his own time, would be the very reverse to another who is not so favoured. But in either case, our rule holds good. For, the more numerous are the objects which a man pursues, under any circumstances, the less time he has to devote to each, and the less improvement he will, consequently, make. By aiming at too much, he may lose all.

On the contrary, by confining, for a time, our attention to those subjects which are the most important, and which are the foundation