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THE SECOND PART OF LOGIC.
Of Judgment and Proposition. WHEN the mind has got acquaiutance with things by framing ideas of them, it proceeds to the next operation, and that is, to compare these ideas together, and to join them by affirmation, or disjoin them by negation, according as we find them to agree or disagree. This act of the miod is called judgment; as when we have by perception obtained the ideas of Plato, a philosopher, man, innocent, we form this judgment; Plato was a philosopher ; no man is innocent.
Some writers have asserted, that judgment consists in a mere perception of the agreement or disagreement of ideas. But I rather think there is an act of the wili (at least in most cases) necessary to form a judgment; for though we do perceive or think we perceive ideas to agree or disagrec, yet we may sometimes refrain from judging or assenting to the perception, for fear least the perception should not be sufficiently clear, and we should be mistaken : and I ain well assured at other times, that there are multitudes of judgments formed, and a firm assent given to ideas joined or disjoined, before there is any clear perception whether they agree or disagree; and this is the reason of so many false judgments or mistakes among men. Both these practices are a proof that judgment has something of the will in in it, and does not merely consist in perception, since we some times judge (though unhappily) without perceiving, and sometimes we perceive without immediate judging.
As an idea is the result of our conception or apprehension, so a proposition is the effect of judgment. The foregoing sentences which are examples of the act of judgment are properly called propositions. Plato is a philosopher, šc.
Here let us consider: 1. The general nature of a propo. sition, and the parts of which it is composed. 2. The various divisions or kinds of propositions. 3. The springs of false judgment, or the doctrine of prejudices. 4. General directions to assist us in judging aright. 3. Special rules to direct us in judging particular objects.
CHAP. I.-Of the Nature of a Proposition, and its several
Parts. A Proposition is a sentence wherein two or more ideas or terms are joined or disjoined by one affirmation or negation ; as Plato was a philosopher: every angle is formed by two lines meeting : no man living on earth can be completely happy. When there are ever se inany ideas or terms in the sentence, yet if they are joined and disjoined merely by one single affirmation or negation, they are properly called but one proposition, though they inay be resolved into several propositions which are implied therein, as will appear hereafter.
In describing a proposition, I use the word terms as well as ideas, because when mere ideas are joined in the mind without words, it is rather called a judgment ; but when clothed with words, it is called a proposition, even though it be in the mind only, as well as when it is expressed by speaking or writing.
There are three things which go to the nature and consti. tution of a proposition, namely, the subject, the predicate, and the copula.
The subject of a proposition is that concerning which any thing is affirmed or denied. So, Plato, angle, man living or earth, are the subjects of the foregoing propositions.
The predicate is that which is affirmed or denied of the subject; so philosopher is the predicate of the first proposition; formed by two lines meeting, is the predicate of the second ; capable of being completely happy, the proper predicate of the third.
The subject and predicate of a proposition taken together, are called the matter of it; for these are the materials of which it is made.
The copula is the form of a proposition ; it represents the act of the mind affirming or denying, and it is expressed by the words, am, art, is, are, &c. or am not, art not, is not, are not, &c.
It is not a thing of importance enough to create a dispute, whether the words, no, none, not, never, &c. which disjoin the idea or terms in a negative proposition, shall be called a part of the subject of the copula, or of the predicate. Sometimes perhaps they may seem most naturally to be included in one, and sometimes in another of these, though a proposition is usually denominated affirmative or negative from its copula, as fiereafter :
Note 1. Where each of these parts of a proposition is not expressed distinctly in so many words, yet they are all understood, and implicitly contained therein; as Socrates disputed, is a complete proposition, for it signifies Socrates was disputing. So I die, signifies I am dying. I can write, that is, I am able to write. In Latin and Greek, one single word is many times a complete proposition.
2. These words, am, art, is, &c. when they are used alone without any other predicate, signifying both the act of the mind judging, which includes the copula, aud signify also actual existence, which is the predicate of that proposition. So Rome is; siguifies Rome is existent; there are some strange monsters,
that is, some strange monsters are existent; Carthage is no more, that is, Carthage bas no being.
3. The subject and predicate of a proposition, are not always to be known and distinguished by the placing of the words in the sentence, but by reflecting duly on the sense of the words, and on the mind or design of the speaker or writer : as if I say, in Africa there are many lions, I mean many lions are existent in Africa : many liops is the subject, and existent in Africa is the predicate. It is proper for a philosopher to understand geome. try; here the word proper is the predicate, and all the rest is the subject, except Is the copula.
4. The subject and predicate of a proposition ought always to be two different ideas, or two different terms; for where both the terms and ideas are the same, it is called an identical proposition, which is mere trifling, and cannot tend to promote knowledge; such as, a rule is a rule, or a good man is a good man.
But there are some propositions, wherein the terms of the subject and predicate seem to be the same; yet the ideas are not the same; nor can these be called purely identical or trifling propositions ; such as home is home; that is, home is a conveni ent or delightful place; Socrates is Socrates still : that is, the man Socrates is still a philosopher : the hero was not a hero ; that is, the hero did not shew his courage; what I have written I have written; that is, what I wrote I still approve, and will not alter it: what is done, is done ; that is, it cannot be undone. It may be casily observed in these propositions the term is equivocal, for in the predicate it has a different idea from what it has in the subject.
There are also some propositions wherein the terms of the subject and predicate differ, but the ideas are the same ; and these are not merely identical or trifling propositions as impudent is shameless; a billow is a wave; or fluctus (in Latin) is a wate; a globe is a round body. In these propositions either the words are explained by a definition of the name, or the ideas by a definition of the thing, and therefore they are by no means useless, when formed for this purpose.
CHAP. II.-Of the various Kinds of Propositions.
PROPOSITIONS may be distributed into various kinds, according to their subject, their copula, their predicate, their nature or composition, their sense, and their evidence, which distributions will be explained in the following sections : Sect. 1.-Of universal, particular, indefinite, and singular
ject into universal and particular; this is usually called a division, arising from the quantity.
An universal proposition is when the subject is taken according to the whole of its extension ; so if the subject be a genus, or general nature, it includes all its species or kiods : if the subject be a species, it includes all its individuals. This universality is usually signified by these words, all, every, no, none, or the like; as, all men must die; no man is almighty: every creature had a beginning.
A particular proposition is when the subject is not taken according to its wbole extension; that is, when the terra is limited and restrained to some one or more of those species or individuals, whose general nature it expresses, but reaches not to all; and this is usually denoted by the words, some, many, a few, there are, which, &c. as, some birds can sing well : few men are truly wise :
ere are parrots
ich will k a hundred things.
Under the general name of universal propositions, we may justly include those that are singular, and for the most part those that are indefinite also.
A singular proposition is wben the subject is a singular or individual term or idea; as Descartes was an ingenious pbilosopher: Sir Isaac Newton has far exceeded all bis predecessors: ihe palace at Hampton Court is a pleasant dwelling : this day is very cold. The subject here must be taken according to the whole of its extension, because being an individual, it can extend only to one, and it must therefore be regulated by the laws of universal propositions.
An indefinite proposition, is when no note, either of universality or particularity, is prefixed to a subject, which is in its own nature general; as a planet is ever changing its place; angels are noble creatures. Now this sort of proposition, espe cially when it describes the nature of things, is usually counted universal also, and it supposes the subject to be taken in its whole extension ; for if there were any planet which did not change its place, or any angel that were not a noble creature, these propo. sitions would not be strictly true.
Yet in order to secure us against mistakes in judging of universal, particular, aud indefinite propositions, it is necessary to make these following remarks :
1. Concerning universal propositions.
Note 1. Universal terms may either denote a metaphysical, a physicul, or a moral universality.
A metaphysical or mathematical universality, is when all the particulars contained under any general idea bave the saine predicate belonging to thein without any exception whatsoever ; or when the predicate is so essential to the universal subject, that it destroys the very nature of the subject to be without it; as, all
circles have a centre and circumference : all spirits in their own nature are immortal.
A physical or natural universality, is when according to the order and common course of nature, a predicate agrees to all the subjects of that kind, though there may be some accidental and preternatural exceptions, as, all men use words to express their thoughts, yet dumb persons are excepted, for they cannot speak. · All beasts have four feet, yet there may be some monsters with five; or maimed, who have but three.
A moral universality, is when the predicate agrees to the greatest part of the particulars which are contaioed under the universal subject; as, all negroes are stupid creatures : all men are governed by affection rather than by reason : all the old Romans loved their country: and the scripture uses this language, when St. Paul tells us, the Cretes are always liars.
Now it is evident, that a special or singular conclusion cannot be inferred from a moral universality, nor always and infallibly from a physical one, though it may be always inferre i from a universality which is metaphysical, without any danger or possibility of a mistake.
Let it be observed also, that usually we make little or no distinction in common language, between a subject that is physically or metaphysically universal.
Note 2. An universal term is sometimes taken collectively for all its particular ideas united together, and sometimes distributively, meaning each of them single aloue.
lostances of a collective universal are such as these : all these apples will fill a bushel, all the hours of the night are sufficient for sleep : all the rules of grammar overload the meinory. In these propositions it is evident, that the predicate belongs not to the individuals separately, but to the whole collective iclea; for we cannot affirnu the same predicate if we change the word all into one or into every; we cannot say one apple or every apple will fill a bushel, &c. Now such a collective idea, when it becoines the subject of a proposition, ought to be esteemed as one single thing, and this renders the proposition singular or indefi. pite, as we shall shew immediately.
A distributive unitersal will allow the word all to be changed into every, or into one, and by this means is distinguished from a collective.
Instances of a distribute universal are the most common on every occasion ; as all men are mortal : every man is a sioner, &c. But in this sort of universal there is a distribution to be. inade, which follows in the remark.
***, Note 3. When an universal term is taken distributively, sometimes it ircludes all the individuals contained in its inferior species : as when I say every sickness has a teudency to death; I mean every individual sickness, as well as every kind. But