A proposition, we have before said, is a portion of discourse1 in which a predicate is affirmed or denied of a subject. A predicate and a subject are all that is necessarily required to make up a proposition: but as we cannot conclude from merely seeing two names put together, that they are a predicate and a subject, that is, that one of them is intended to be affirmed or denied of the other, it is necessary that there should be some mode or form of indicating that such is the intention; some sign to distinguish a predication from any other kind of discourse. This is sometimes done by a slight alteration3 of one of the words, called an inflection; as when we say, Fire burns; the change of the second word from burn to burns showing that we mean to affirm the predicate burn of the subject fire. But this function is more commonly fulfilled by the word is, when an affirmation is intended, is not, when a negation4; or by some other part of the verb to be. The word which thus serves the purpose of a sign of predication is called, as we formerly5 observed, the copula. It is important that there should be no indistinctness in our conception of the nature and office of the copula; for confused notions respecting it are among the causes which have spread mysticism over the field of logic6, and perverted7 its speculations9 into logomachies.
It is apt to be supposed that the copula is something more [Pg 86]than a mere2 sign of predication; that it also signifies existence. In the proposition, Socrates is just, it may seem to be implied not only that the quality just can be affirmed of Socrates, but moreover that Socrates is, that is to say, exists. This, however, only shows that there is an ambiguity10 in the word is; a word which not only performs the function of the copula in affirmations, but has also a meaning of its own, in virtue11 of which it may itself be made the predicate of a proposition. That the employment of it as a copula does not necessarily include the affirmation of existence, appears from such a proposition as this, A centaur12 is a fiction of the poets; where it cannot possibly be implied that a centaur exists, since the proposition itself expressly asserts that the thing has no real existence.
Many volumes might be filled with the frivolous13 speculations concerning the nature of Being, (το ?ν, ο?σ?α, Ens, Entitas, Essentia, and the like) which have arisen from overlooking this double meaning of the word to be; from supposing that when it signifies to exist, and when it signifies to be some specified14 thing, as to be a man, to be Socrates, to be seen or spoken of, to be a phantom15, even to be a nonentity16, it must still, at bottom, answer to the same idea; and that a meaning must be found for it which shall suit all these cases. The fog which rose from this narrow spot diffused17 itself at an early period over the whole surface of metaphysics. Yet it becomes us not to triumph over the great intellects of Plato and Aristotle because we are now able to preserve ourselves from many errors into which they, perhaps inevitably18, fell. The fire-teazer of a modern steam-engine produces by his exertions19 far greater effects than Milo of Crotona could, but he is not therefore a stronger man. The Greeks seldom knew any language but their own. This rendered it far more difficult for them than it is for us, to acquire a readiness in detecting ambiguities20. One of the advantages of having accurately21 studied a plurality of languages, especially of those languages which eminent22 thinkers have used as the vehicle of their thoughts, is the practical lesson we learn respecting the ambiguities of words, by finding that the same word in one language [Pg 87]corresponds, on different occasions, to different words in another. When not thus exercised, even the strongest understandings find it difficult to believe that things which have a common name, have not in some respect or other a common nature; and often expend23 much labour very unprofitably (as was frequently done by the two philosophers just mentioned) in vain attempts to discover in what this common nature consists. But, the habit once formed, intellects much inferior are capable of detecting even ambiguities which are common to many languages: and it is surprising that the one now under consideration, though it exists in the modern languages as well as in the ancient, should have been overlooked by almost all authors. The quantity of futile24 speculation8 which had been caused by a misapprehension of the nature of the copula, was hinted at by Hobbes; but Mr. James Mill[15] was, I believe, the first who distinctly characterized the ambiguity, and pointed25 out how many errors in the received systems of philosophy it has had to answer for. It has indeed misled the moderns scarcely less than the ancients, though their mistakes, because our understandings are not yet so completely emancipated26 from their influence, do not appear equally irrational27.
We shall now briefly28 review the principal distinctions which exist among propositions, and the technical terms most commonly in use to express those distinctions.
§ 2. A proposition being a portion of discourse in which something is affirmed or denied of something, the first division of propositions is into affirmative and negative. An affirmative proposition is that in which the predicate is affirmed of the subject; as, C?sar is dead. A negative proposition is that in which the predicate is denied of the subject; as, C?sar is not dead. The copula, in this last species of proposition, consists of the words is not, which are the sign of negation; is being the sign of affirmation.
Some logicians, among whom may be mentioned Hobbes, [Pg 88]state this distinction differently; they recognise only one form of copula, is, and attach the negative sign to the predicate. "C?sar is dead," and "C?sar is not dead," according to these writers, are propositions agreeing not in the subject and predicate, but in the subject only. They do not consider "dead," but "not dead," to be the predicate of the second proposition, and they accordingly define a negative proposition to be one in which the predicate is a negative name. The point, though not of much practical moment, deserves notice as an example (not unfrequent in logic) where by means of an apparent simplification, but which is merely verbal, matters are made more complex than before. The notion of these writers was, that they could get rid of the distinction between affirming and denying, by treating every case of denying as the affirming of a negative name. But what is meant by a negative name? A name expressive30 of the absence of an attribute. So that when we affirm a negative name, what we are really predicating is absence and not presence; we are asserting not that anything is, but that something is not; to express which operation no word seems so proper as the word denying. The fundamental distinction is between a fact and the non-existence of that fact; between seeing something and not seeing it, between C?sar's being dead and his not being dead; and if this were a merely verbal distinction, the generalization31 which brings both within the same form of assertion would be a real simplification: the distinction, however, being real, and in the facts, it is the generalization confounding the distinction that is merely verbal; and tends to obscure the subject, by treating the difference between two kinds of truths as if it were only a difference between two kinds of words. To put things together, and to put them or keep them asunder32, will remain different operations, whatever tricks we may play with language.
A remark of a similar nature may be applied33 to most of those distinctions among propositions which are said to have reference to their modality; as, difference of tense or time; the sun did rise, the sun is rising, the sun will rise. These [Pg 89]differences, like that between affirmation and negation, might be glossed34 over by considering the incident of time as a mere modification35 of the predicate: thus, The sun is an object having risen, The sun is an object now rising, The sun is an object to rise hereafter. But the simplification would be merely verbal. Past, present, and future, do not constitute so many different kinds of rising; they are designations belonging to the event asserted, to the sun's rising to-day. They affect, not the predicate, but the applicability of the predicate to the particular subject. That which we affirm to be past, present, or future, is not what the subject signifies, nor what the predicate signifies, but specifically and expressly what the predication signifies; what is expressed only by the proposition as such, and not by either or both of the terms. Therefore the circumstance of time is properly considered as attaching to the copula, which is the sign of predication, and not to the predicate. If the same cannot be said of such modifications36 as these, C?sar may be dead; C?sar is perhaps dead; it is possible that C?sar is dead; it is only because these fall altogether under another head, being properly assertions not of anything relating to the fact itself, but of the state of our own mind in regard to it; namely, our absence of disbelief of it. Thus "C?sar may be dead" means "I am not sure that C?sar is alive."
§ 3. The next division of propositions is into Simple and Complex. A simple proposition is that in which one predicate is affirmed or denied of one subject. A complex proposition is that in which there is more than one predicate, or more than one subject, or both.
At first sight this division has the air of an absurdity37; a solemn distinction of things into one and more than one; as if we were to divide horses into single horses and teams of horses. And it is true that what is called a complex proposition is often not a proposition at all, but several propositions, held together by a conjunction. Such, for example, is this: C?sar is dead, and Brutus is alive: or even this, C?sar is dead, but Brutus is alive. There are here two distinct [Pg 90]assertions; and we might as well call a street a complex house, as these two propositions a complex proposition. It is true that the syncategorematic words and and but have a meaning; but that meaning is so far from making the two propositions one, that it adds a third proposition to them. All particles are abbreviations, and generally abbreviations of propositions; a kind of short-hand, whereby something which, to be expressed fully38, would have required a proposition or a series of propositions, is suggested to the mind at once. Thus the words, C?sar is dead and Brutus is alive, are equivalent to these: C?sar is dead; Brutus is alive; it is desired that the two preceding propositions should be thought of together. If the words were, C?sar is dead but Brutus is alive, the sense would be equivalent to the same three propositions together with a fourth; "between the two preceding propositions there exists a contrast:" viz. either between the two facts themselves, or between the feelings with which it is desired that they should be regarded.
In the instances cited the two propositions are kept visibly distinct, each subject having its separate predicate, and each predicate its separate subject. For brevity, however, and to avoid repetition, the propositions are often blended together: as in this, "Peter and James preached at Jerusalem and in Galilee," which contains four propositions: Peter preached at Jerusalem, Peter preached in Galilee, James preached at Jerusalem, James preached in Galilee.
We have seen that when the two or more propositions comprised in what is called a complex proposition are stated absolutely, and not under any condition or proviso, it is not a proposition at all, but a plurality of propositions; since what it expresses is not a single assertion, but several assertions, which, if true when joined, are true also when separated. But there is a kind of proposition which, though it contains a plurality of subjects and of predicates, and may be said in one sense of the word to consist of several propositions, contains but one assertion; and its truth does not at all imply that of the simple propositions which compose it. An example of this is, when the simple propositions are connected [Pg 91]by the particle or; as, Either A is B or C is D; or by the particle if; as, A is B if C is D. In the former case, the proposition is called disjunctive, in the latter, conditional39: the name hypothetical was originally common to both. As has been well remarked by Archbishop Whately and others, the disjunctive form is resolvable into the conditional; every disjunctive proposition being equivalent to two or more conditional ones. "Either A is B or C is D," means, "if A is not B, C is D; and if C is not D, A is B." All hypothetical propositions, therefore, though disjunctive in form, are conditional in meaning; and the words hypothetical and conditional may be, as indeed they generally are, used synonymously. Propositions in which the assertion is not dependent on a condition, are said, in the language of logicians, to be categorical.
An hypothetical proposition is not, like the pretended complex propositions which we previously40 considered, a mere aggregation41 of simple propositions. The simple propositions which form part of the words in which it is couched, form no part of the assertion which it conveys. When we say, If the Koran comes from God, Mahomet is the prophet of God, we do not intend to affirm either that the Koran does come from God, or that Mahomet is really his prophet. Neither of these simple propositions may be true, and yet the truth of the hypothetical proposition may be indisputable. What is asserted is not the truth of either of the propositions, but the inferribility of the one from the other. What, then, is the subject, and what the predicate of the hypothetical proposition? "The Koran" is not the subject of it, nor is "Mahomet:" for nothing is affirmed or denied either of the Koran or of Mahomet. The real subject of the predication is the entire proposition, "Mahomet is the prophet of God;" and the affirmation is, that this is a legitimate42 inference from the proposition, "The Koran comes from God." The subject and predicate, therefore, of an hypothetical proposition are names of propositions. The subject is some one proposition. The predicate is a general relative name applicable to propositions; of this form—"an inference from so and so." A fresh instance [Pg 92]is here afforded of the remark, that particles are abbreviations; since "If A is B, C is D," is found to be an abbreviation of the following: "The proposition C is D, is a legitimate inference from the proposition A is B."
The distinction, therefore, between hypothetical and categorical propositions, is not so great as it at first appears. In the conditional, as well as in the categorical form, one predicate is affirmed of one subject, and no more: but a conditional proposition is a proposition concerning a proposition; the subject of the assertion is itself an assertion. Nor is this a property peculiar43 to hypothetical propositions. There are other classes of assertions concerning propositions. Like other things, a proposition has attributes which may be predicated of it. The attribute predicated of it in an hypothetical proposition, is that of being an inference from a certain other proposition. But this is only one of many attributes that might be predicated. We may say, That the whole is greater than its part, is an axiom in mathematics: That the Holy Ghost proceeds from the Father alone, is a tenet of the Greek Church: The doctrine44 of the divine right of kings was renounced45 by Parliament at the Revolution: The infallibility of the Pope has no countenance46 from Scripture47. In all these cases the subject of the predication is an entire proposition. That which these different predicates are affirmed of, is the proposition, "the whole is greater than its part;" the proposition, "the Holy Ghost proceeds from the Father alone;" the proposition, "kings have a divine right;" the proposition, "the Pope is infallible."
Seeing, then, that there is much less difference between hypothetical propositions and any others, than one might be led to imagine from their form, we should be at a loss to account for the conspicuous48 position which they have been selected to fill in treatises49 on logic, if we did not remember that what they predicate of a proposition, namely, its being an inference from something else, is precisely50 that one of its attributes with which most of all a logician29 is concerned.
[Pg 93]
§ 4. The next of the common divisions of Propositions is into Universal, Particular, Indefinite, and Singular: a distinction founded on the degree of generality in which the name, which is the subject of the proposition, is to be understood. The following are examples:
All men are mortal— Universal.
Some men are mortal— Particular.
Man is mortal— Indefinite.
Julius C?sar is mortal— Singular.
The proposition is Singular, when the subject is an individual name. The individual name needs not be a proper name. "The Founder51 of Christianity was crucified," is as much a singular proposition as "Christ was crucified."
When the name which is the subject of the proposition is a general name, we may intend to affirm or deny the predicate, either of all the things that the subject denotes, or only of some. When the predicate is affirmed or denied of all and each of the things denoted by the subject, the proposition is universal; when of some undefined portion of them only, it is particular. Thus, All men are mortal; Every man is mortal; are universal propositions. No man is immortal52, is also an universal proposition, since the predicate, immortal, is denied of each and every individual denoted by the term man; the negative proposition being exactly equivalent to the following, Every man is not-immortal. But "some men are wise," "some men are not wise," are particular propositions; the predicate wise being in the one case affirmed and in the other denied not of each and every individual denoted by the term man, but only of each and every one of some portion of those individuals, without specifying53 what portion; for if this were specified, the proposition would be changed either into a singular proposition, or into an universal proposition with a different subject; as, for instance, "all properly instructed men are wise." There are other forms of particular propositions; as, "Most men are imperfectly educated:" it being immaterial how large a portion of the subject the predicate is asserted of, as long as it is left uncertain how that portion is to be distinguished54 from the rest.
[Pg 94]
When the form of the expression does not clearly show whether the general name which is the subject of the proposition is meant to stand for all the individuals denoted by it, or only for some of them, the proposition is, by some logicians, called Indefinite; but this, as Archbishop Whately observes, is a solecism, of the same nature as that committed by some grammarians when in their list of genders55 they enumerate57 the doubtful gender56. The speaker must mean to assert the proposition either as an universal or as a particular proposition, though he has failed to declare which: and it often happens that though the words do not show which of the two he intends, the context, or the custom of speech, supplies the deficiency. Thus, when it is affirmed that "Man is mortal," nobody doubts that the assertion is intended of all human beings; and the word indicative of universality is commonly omitted, only because the meaning is evident without it. In the proposition, "Wine is good," it is understood with equal readiness, though for somewhat different reasons, that the assertion is not intended to be universal, but particular.[16]
When a general name stands for each and every individual which it is a name of, or in other words, which it denotes, it is said by logicians to be distributed, or taken distributively. Thus, in the proposition, All men are mortal, the subject, Man, is distributed, because mortality is affirmed of each and every man. The predicate, Mortal, is not distributed, because the only mortals who are spoken of in the proposition are those who happen to be men; while the word may, for aught that appears, and in fact does, comprehend within it an indefinite number of objects besides men. In the proposition, Some men are mortal, both the predicate and the subject are undistributed. In the following, No men have wings, both the predicate and the subject are distributed. Not only is the attribute of having wings denied of the entire class Man, but that class is severed58 and cast out from the whole of the class Winged, and not merely from some part of that class.
This phraseology, which is of great service in stating and demonstrating the rules of the syllogism59, enables us to express very concisely60 the definitions of an universal and a particular proposition. An universal proposition is that of which the subject is distributed; a particular proposition is that of which the subject is undistributed.
There are many more distinctions among propositions than those we have here stated, some of them of considerable importance. But, for explaining and illustrating61 these, more suitable opportunities will occur in the sequel.
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1
discourse
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| n.论文，演说；谈话；话语；vi.讲述，著述 | |
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mere
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| adj.纯粹的；仅仅，只不过 | |
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alteration
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| n.变更，改变；蚀变 | |
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4
negation
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| n.否定；否认 | |
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formerly
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| adv.从前，以前 | |
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logic
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| n.逻辑(学)；逻辑性 | |
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perverted
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| adj.不正当的v.滥用( pervert的过去式和过去分词 )；腐蚀；败坏；使堕落 | |
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speculation
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| n.思索，沉思；猜测；投机 | |
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speculations
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| n.投机买卖( speculation的名词复数 )；思考；投机活动；推断 | |
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ambiguity
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| n.模棱两可；意义不明确 | |
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virtue
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| n.德行，美德；贞操；优点；功效，效力 | |
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centaur
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| n.人首马身的怪物 | |
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frivolous
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| adj.轻薄的；轻率的 | |
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specified
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| adj.特定的 | |
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phantom
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| n.幻影，虚位，幽灵；adj.错觉的，幻影的，幽灵的 | |
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nonentity
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| n.无足轻重的人 | |
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diffused
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| 散布的，普及的，扩散的 | |
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inevitably
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| adv.不可避免地；必然发生地 | |
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exertions
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| n.努力( exertion的名词复数 )；费力；（能力、权力等的）运用；行使 | |
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ambiguities
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| n.歧义( ambiguity的名词复数 )；意义不明确；模棱两可的意思；模棱两可的话 | |
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accurately
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| adv.准确地，精确地 | |
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eminent
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| adj.显赫的，杰出的，有名的，优良的 | |
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expend
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| vt.花费，消费，消耗 | |
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futile
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| adj.无效的，无用的，无希望的 | |
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pointed
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| adj.尖的，直截了当的 | |
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emancipated
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| adj.被解放的，不受约束的v.解放某人（尤指摆脱政治、法律或社会的束缚）( emancipate的过去式和过去分词 ) | |
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irrational
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| adj.无理性的，失去理性的 | |
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briefly
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| adv.简单地，简短地 | |
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logician
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| n.逻辑学家 | |
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expressive
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| adj.表现的，表达…的，富于表情的 | |
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generalization
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| n.普遍性，一般性，概括 | |
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asunder
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| adj.分离的，化为碎片 | |
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applied
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| adj.应用的；v.应用，适用 | |
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glossed
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| v.注解( gloss的过去式和过去分词 )；掩饰（错误）；粉饰；把…搪塞过去 | |
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modification
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| n.修改，改进，缓和，减轻 | |
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modifications
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| n.缓和( modification的名词复数 )；限制；更改；改变 | |
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absurdity
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| n.荒谬，愚蠢；谬论 | |
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fully
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| adv.完全地，全部地，彻底地；充分地 | |
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conditional
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| adj.条件的，带有条件的 | |
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previously
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| adv.以前，先前（地） | |
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aggregation
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| n.聚合，组合；凝聚 | |
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legitimate
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| adj.合法的，合理的，合乎逻辑的；v.使合法 | |
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peculiar
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| adj.古怪的，异常的；特殊的，特有的 | |
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doctrine
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| n.教义；主义；学说 | |
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45
renounced
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| v.声明放弃( renounce的过去式和过去分词 )；宣布放弃；宣布与…决裂；宣布摒弃 | |
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countenance
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| n.脸色，面容；面部表情；vt.支持，赞同 | |
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47
scripture
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| n.经文，圣书，手稿；Scripture:(常用复数)《圣经》，《圣经》中的一段 | |
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conspicuous
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| adj.明眼的，惹人注目的；炫耀的，摆阔气的 | |
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treatises
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| n.专题著作，专题论文，专著( treatise的名词复数 ) | |
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50
precisely
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| adv.恰好，正好，精确地，细致地 | |
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Founder
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| n.创始者，缔造者 | |
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immortal
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| adj.不朽的；永生的，不死的；神的 | |
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53
specifying
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| v.指定( specify的现在分词 )；详述；提出…的条件；使具有特性 | |
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distinguished
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| adj.卓越的，杰出的，著名的 | |
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genders
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| n.性某些语言的（阳性、阴性和中性，不同的性有不同的词尾等）( gender的名词复数 )；性别；某些语言的（名词、代词和形容词）性的区分 | |
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gender
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| n.（生理上的）性，（名词、代词等的）性 | |
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enumerate
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| v.列举，计算，枚举，数 | |
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58
severed
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| v.切断，断绝( sever的过去式和过去分词 )；断，裂 | |
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59
syllogism
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| n.演绎法，三段论法 | |
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60
concisely
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| adv.简明地 | |
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61
illustrating
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| 给…加插图( illustrate的现在分词 )； 说明； 表明； （用示例、图画等）说明 | |
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