In 1724 Isaac Watts publishes the standard treatise on the study of Logic. In the introduction he defines the purpose and organization of his study.
Reason as to the Power and Principle of it, is the common Gift of God to all Men; tho’ all are not favoured with it by Nature in an equal Degree: But the acquired Improvement of it in different Men, make a much greater Distinction between them than Nature had made.
The Right Use of REASON.
ENQUIRY after TRUTH.
The INTRODUCTION and general SCHEME.
LOGICK is the Art of using Reason* well in our Enquiries after Truths and the Communication of it to others.
Reason* is the Glory of human Nature, and one of the chief Eminencies whereby we are raised above our Fellow-creatures the Brutes in this lower World.
* 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.
Reason as to the Power and Principle of it, is the common Gift of God to all Men; tho’ all are not favoured with it by Nature in an equal Degree: But the acquired Improvement 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 Logick is to teach us the right Use of our Reason, or Intellectual Powers, and the Improvement of them in our selves 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 Falshoood: 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 arrive 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.
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 Logick 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 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 Falshoods. So Knavery puts on the Face of Justice, Hypocrisy and Superstition wear the Vizard of Piety, Deceit and Evil are often cloathed in the Shapes and Appearances of Truth and Goodness. Now Logick helps us to strip off the outward Disguise of Things, and to behold them and judge of them in their own Nature.
There is yet a farther Proof of 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 Logick 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 Assistance 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 may prove fatal too.
The Art of Logick, 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 Logick: And it is but a higher Advancement, and a farther Assistance of our rational Powers that is designed by and expected from this artificial Logick.
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 Logick is composed of those Observations and Rules, which Men have made about these four Operations of the Mind, Perception, Judgment, Reasoning, and Disposition, in order to assist and improve them.
I. 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, 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, whereby we join two or more Ideas together by one Affirmation 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; Mere 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 Propostions.
III. Argumentation or Reasoning is that Operation of the Mind, whereby we infer one Thing, i. e. one Proposition, from two or more Propositions premised. Or it is the drawing a Conclusion, which before was either unknown, or dark, or doubtfull, from some Propositions which are more known and evident. So when we have judged that Matter cannot think, and that the Mind of Man doth think, we then infer and conclude, that therefore the Mind of Man is not Matter.
So we judge that A just Governor will make a Difference between the Evil and the Good; we judge also that God is a just Governor; and from thence we conclude, that God will make a Difference betwixt the Evil and the Good.
This Argumentation may be carried on farther, thus, God will one Time or another make a Difference between the Good and the Evil: But there is little or no Difference made in this World; Therefore there must be another World wherein this Difference
shall be made.
These Inferences or Conclusions are the Effects of Reasoning, and the three Propositions taken all together are called a Syllogism, or Argument.
IV. Disposition is that Operation of the Mind, whereby we put the Ideas, Propositions and Arguments, which we have formed concerning one Subject, into such an Order as is fittest to gain the cleared Knowledge of it, to retain it longest, and to explain it to others in the best Manner: Or, in short, it is the Ranging of our Thoughts in such Order, as is best for our own and others Conception and Memory. The Effect of this Operation is called Method. This very Description of the four Operations of the Mind and their Effects in this Order, is an Instance or Example of Method.
Now as the Art of Logick assists our Conception, so it gives us a large and comprehensive View of the Subjects we enquire into, as well as a clear and distinct Knowledge of them. As it regulates our Judgment and our Reasoning, so it secures us from Mistakes, and gives us a true and certain Knowledge of Things; and as it furnishes us with Method, so it makes our Knowledge of Things both easy and regular, and guards our Thoughts from Confusion.
Logick is divided into four Parts, according to these four Operations of the Mind, which it directs, and therefore we shall treat of it in this Order.