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Sect. 4. Of pure and modal propositions


Sect. 5. Of single propositions, whether simple or complex 129

Sect. 6. Of compound propositions


Sect. 7. Of true and false propositions


Sect. 8. Of certain and dubious propositions, of knowledge

and opinion


Sect. 9. Of sense, consciousness, intelligence, reason, faith,

and inspiration


CHAP. 111 - The Springs of false Judgment, or the Doc.

trine of Prejudices


Sect. 1. Prejudices arising from things


Sect. 2. Prejudices arising from words


Sect. 3. Prejudices arising from ourselves


Sect. 4. Prejudices arising from other persons


CHAP. IV.-General Directions to ussist us in judging



CHAP. V. Special Rules to direct us in judging of purti.

cular Objects


Sect. 1. Principles and rules of judgment concerning the

objects of sense


Sect. 3. Principles and rules of judgment in matters of rea.

son and speculation


Sect. 3. Principles and rules of judgment in matters of mo!

rality and religion


Sect. 4. Principles and rules of judgment in matters of nu.

man prudence


Sect. 5. Principles and rules of judgment in matters of hu.
man testimony


Sect. 6. Principles and rules of judgment in matters of di.

vine testimony


Sect. 7. Principles and rules of judging concerning things

past, present, and to come, by the mere use of


CHAP. I.-Of the Nature of a Syllogism, and of the Parts ...

of which it is composed


CHAP, 11.-Oj'the various kinds of syllogisms, with par.

ticular Rules relating to them


Sect. 1. Of universul and particular syllogisms, both nega-
tive and artırmative

Sect. 2. Of plain sinple syllogisms, and their rules


Sect 3 of the moods and figures of simple syllogisms 926

Sect. 4 Of complex syllogisms


Sect. 5. Of conjunctive syll gisms


Sect. 6. Of compound syllogisms

Sect. 7. Of the middle cerms, of common places or topics,

and invention of arguments


Sect. 8. Of several kinds of arguments and demonstrations 240

CHAP. III.-The Doctrine of Syllogisms


Sect. 1. Of several kinds of sophisms and their solution

Sect. 2. Two general tests of true syllogismus,, and methods

of solving all sophisms


CHAP. IV.-Some general Rules to direct our Reasoning 955


CHAP. I.--The Nature and kinds of Kethod, viz. natural

and arbitrary, synthetic and anulytá

SHAP. II.--Generul und special Rules Method


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LOGIC is the art of using reason* well in our en

quiries after truth, and the communication of it to others.

Reason* is the glory of human nature, and one of the chief eminences whereby we are raised above our fellow-creatures the brutes in this lower worid.

Reason, as to the power and principle of it, is the common gift of God to all men, though all are not favoured with it by nature in an equal degree; but the acquired improvements of it in different men, make a much greater distinction between them than nature had made. I could even venture to say, that the ime, provement of reason hath raised the learned and the prudent in the European world almost as much above the Hottentots, and other savages of Africa, as those savages are by nature superior to the birds, the beasts, and the fishes.

Now the design of Logic is to teach us the right use of our reason, or intellectual powers, and the improvement of them in ourselves and others. This is pot only necessary in order to attain any competent knowledge in the sciences, or the aífairs of learning,

The word Reason in this place is not confined to the inere faculty of reasoning, or inferring one thing from another, but includes all the jotellectual powers of man.


but to govern both the greater and the meaner actions of life. It is the cultivation of our reason by which we are better enabled to distinguish good from evil, as well as truth from falsehood; and both these are matters of the highest importance, whether we regard this life, or the life to come.

The pursuit and acquisition of truth is of infinite concernment to mankind. Herehy we become acquainted with the vame of things both in heaven and earth, and their various relations to each other. It is by this means we discover our duty to God and our fellow-creatures; by this we arrive at the kuowledge of natural religion, and learn to confirm our faith in divine revelation, as well as to understand what is revealed. Our wisdom, prudence, and piety, our present conduct and our future hope, are all influenced by the use of our rational powers in the search after truth.

There are several things that make it very neces. sary that our réason should have some assistance in the exercise or use of it.

The first is, the depth and difficulty of many truths, and the weakness of our reason to see far into things at once,

and penetrate to the bottom of them. It was a saying among the ancients, Veritas in puteo, truth lies in a well; and, to carry on this metaphor, we may very justly say, that logic does, as it were, supply us with steps whereby we may go down to reach the water; or it frames the links of a chain, whereby we may draw the water up from the bottom. Thus, by the means of many reasonings well connected together, philosophers in our age have drawn a thousand truths out of the depths of darkness, which our. fathers were utterly unacquainted with:

Another thing that makes it necessary for our reason to have some assistance given it, is the disguise and false colours in which many things appear to us in this present imperfect state. There are a thousand things which are not in reality what they appear to be, and that both in the natural and moral world : so that the sun appears to be flat as a plate of silver, and to be less than twelve inches in diameter;

the moon appears to be as big as the sun; and the rainbow appears to be a large substantial arch in the sky: all which are in reality gross falsehoods. Su knavery puts on the face of justice; lıypocrisy and superstition wear the vizard of piety; deceit and evil are often cloathed in the shapes and appearances of truth and gooduess. Now logic helps us to strip off the outward disguise of things, and to behold them and judge of them iu their own nature.

There is yet a farther proof of our intellectual or ra. tional powers needing some assistance, and that is, because they are so frail and fallible in the present state. We are imposed upon at home as weli as abroad; we are deceived by our senses, by our imaginations, by our passions and appetites; by the authu. rity of men, by education and custom, &c.; and we are led into frequent errors, by judging according to these false and flattering principles, rather than arcording to the nature of things. Something of this frailty is owing to our very constitution, man being compounded of Aesh and spirit; something of it arises from our infant state, and our growing up by small degrees to manhood; so that we furin a thousand judgments before our reason is mature. But there is still more of it owing to our original defection from God, and the foolish and evil dispositions that are found in fallen man; so that one great part of the design of logic is to guard us against the delusive influences of our meaner powers, to cure the mistakes of immature judgment, and to raise us in suine measure from the ruins of our fall.

It is evident enough from all these things, that our reason needs the assistance of art in our enquiries after truth or duty; and without some skill and diligence in forming our judgment aright, we shall be led into frequent mistakes, both in matters of science and in matters of practice; and some of these mistakes may prove fatal too.

The art of logic, even as it assists us to gain the knowledge of the sciences, leads us on towards virtue and happiness : for all our speculative acquaintance with things should be made subservient to our better conduct in the civil and the religious life. This is infinitely more valuable than all speculations, and a wise man will use them chiefly for this better purpose.

All the good judgment and prudence that any man exerts in his common concerns of life, without the advantage of learning, is called natural logic; and it is but a higher advancement, and a farther assistance of our rational powers, that is designed by and expected from this artificial logic.

In order to attain this, we must enquire what are the principal operations of the mind which are put forth in the exercise of our reason; and we shall find them to be these four, viz. Perception, judgment, argumentation and disposition,

Now the art of logic is composed of those observations and rules, which men have made about these four operations of the miud: perception, judgment, reasoning, and disposition, in order to assist and improve them.

1. Perception, conception, or apprehension, is the mere simple contemplation of things offered to our mind, without affirming or denying any thing concerning them. So we conceive or think of a horse, a tree, high, swift, slow, animal, time, motion, matter, mind, life, death, &c. The form under which these things appear to the mind, or the result of our conception or apprehension, is called an idea.

II. Judgment is that operation of the mind wherehy we join two or more ideas together by one affirmatiou or negation; that is, we either affirm or deny this to be that. So this tree is high; that horse is not swift; the mind of man is a thinking being; mére matter has no thought belonging to it; God is just; good men are often miserable in this world; a. righteous governor will make a difference betwixt the evil and the good; which sentences are the effect of judgment, and are called Propositions.

JII. Argumentation, or reasoning, is that operation: of the mind whereby we infer one thing, that is, one proposition, from two or more propositions premised: or, it is the drawing a conclusion, which before was either unkyown, or dark or doubtful, from some pro

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