LOGIC.

SIR,

IT is fit the public should receive through your hands, what was written originally for the assistance of your younger studies, and was then presented to you.

It was by the repeated importunities of our learned friend Mr. John Eames, that I was persuaded to revise the Rudiments of Logic, and when I had once suffered myself to begin the work, I was drawn still onward, far beyond my first design, even to the neglect, or too long delay, of other pressing and important demands that were upon me.

It has been my endeavour to form every part of this Treatise both for the instruction of students, to open their way into the sciences, and for the more -` extensive and general service of mankind, that the Gentleman and the Christian might find their account in the perusal, as well as the Scholar, I have therefore collected and proposed the chief principles and rules of right judg ment in matters of common and sacred importance, and pointed out our most frequent mistakes and prejudices in the concerns of life and religion, that we might better guard against the springs of error, guilt and sorrow, which surround us in our state of mortality.

You know, Sir, the great design of this noble science is to rescue our reasoning powers from their unhappy slavery and darkness; and thus, with all due submission and deference, it offers an humble assistance to divine revelation. Its chief business is to relieve the natural weakenesses of the mind, by some better efforts of nature: It is to diffuse a light over the understanding in our enquiries after truth, and not to furnish the tongue with debate and controversy. True Logic is not that noisy thing that deals all in dispute and wrangling, to which former ages had debased and confined it; yet its disciples must acknowledge also, that they are taught to vindicate and defend the ruth, as well as to search it out. True Logic doth not require a long detail of hard words to amuse mankind, and to puff up the mind with empty sounds, and a pride of false learning; yet some distinctions and terms of art are necessary to range every idea in its proper class, and to keep our thoughts from confusion. The world is now grown so wise, as not to suffer this valua ble art to be engrossed by the schools. In so polite and knowing an age, every man of reason will covet some acquaintance with Logic, since it renders its daily service to wisdom and virtue, and to the affairs of common life, as well as to the sciences.

"I will not presume, Sir, that this little Book is improved since its first composure in proportion to the improvements of your manly age. But when you shall please to review it in your retired hours, perhaps you may refresh your own memory in some of the early parts of learning. And if you find all the additional Remarks and Rules made so familiar to you already by your own observation, that there is nothing new among them, it will be no unpleasing reflection that you have so far anticipated the present zeal and labour of,

Your most faithful

to

INTRODUCTION AND GENERAL SCHEME.

LOGIC is the art of using REASON* well in our enquiries after truth, and the communication of it to others,

REASON* is the glory of human nature, and one of the chief emi nences whereby we are raised above our fellow-creatures, the brutes, in this lower world.

Reason, as to the power and principles 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 "improvement 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 not only necessary in order to attain any competent knowledge in the sciences, or the affairs of learning, 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. Hereby we become acquainted with the nature 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 ar rive at the knowledge 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 necessary that our reason should have some assistance in the exercise or use of it.

This 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 assist

*The word "reason" in this place is not confined to the mere faculty of reasoning, or inferring one thing from another, but includes all the intellectual powers of man.

ance 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 the moral world: so 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. So knavery puts on the face of justice, hypocrisy and superstition wear the vizardof piety, deceit and evil are often clothed in the shapes and appearances of truth and goodness. Now Logic helps to strip off the outward disguise of things, and to behold them, and judge of them in their own nature.

There is yet a further proof that our intellectual or rational powers need some assistance, and that is, because they are so frail and fallible in the present state; we are imposed upon at home as well as abroad; we are deceived by our senses, by our imaginations, by our passions and appetites, by the authority 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 according to the nature of things. Something of this frailty is owing to our very constitution, man being compounded of flesh and spirit; something of it arises from our infant state, and our growing up by small degrees to manhood, so that we form 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 some measure from the ruins of our fall.

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

The art of Logic, even as it assists us to gain the knowledge of the sciences, leads us on toward virtue and happiness: for all our speculative acquaintance with things should be made șubservient to our better conduct in the civil and 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 logiés: and it is but a bigher advancement, and a farther assistance of our rational powers, that is designed by and expected from this artificial Logica

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, namely, 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 mind, perception, judg ment, 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 minds, without affirming or denying any thing concerning them. So we conceive or think of a horse, a tree, high, Twitt, slow, animal, time, motion, matter, mind, life, death, &c. The form