CHAPTER III.

OF PROPOSITION.

1. Divers kinds of speech.—2. Proposition defined.—3. Subject, predicate, and copula, what they are; and abstract and concrete what. 4. The use and abuse of names abstract.—5. Proposition, universal and particular.—6. Affirmative and negative.—7. True and false.—8. True and false belongs to speech, and not to things.—9. Proposition, primary, not primary, definition, axiom, petition.—10. Proposition, necessary and contingent.—11. Categorical and hypothetical.—12. The same proposition diversely pronounced.—13. Propositions that may be reduced to the same categorical proposition, are equipollent.—14. Universal propositions converted by contradictory names, are equipollent.—15. Negative propositions are the same, whether negation be before or after the copula.—16. Particular propositions simply converted, are equipollent.—17. What are subaltern, contrary, subcontrary, and contradictory propositions.—18. Consequence, what it is.—19. Falsity cannot follow from truth.—20. How one proposition is the cause of another.

[Sidenote: Divers kinds of speech.]

1. From the connexion or contexture of names arise divers kinds of speech, whereof some signify the desires and affections of men; such are, first, _interrogations_, which denote the desire of knowing: as, _Who is a good man?_ In which speech there is one name expressed, and another desired and expected from him of whom we ask the same. Then _prayers_, which signify the desire of having something; _promises_, _threats_, _wishes_, _commands_, _complaints_, and other significations of other affections. Speech may also be absurd and insignificant; as when there is a succession of words, to which there can be no succession of thoughts in mind to answer them; and this happens often to such, as, understanding nothing in some subtle matter, do, nevertheless, to make others believe they understand, speak of the same incoherently; for the connection of incoherent words, though it want the end of speech (which is signification) yet it is speech; and is used by writers of _metaphysics_ almost as frequently as speech significative. In philosophy, there is but one kind of speech useful, which some call in Latin _dictum_, others _enuntiatum et pronunciatum_; but most men call it _proposition_, and is the speech of those that affirm or deny, and expresseth truth or falsity.

[Sidenote: Proposition defined.]

2. _A_ PROPOSITION _is a speech consisting of two names copulated, by which he that speaketh signifies he conceives the latter name to be the name of the same thing whereof the former is the name; or_ (which is all one) _that the former name is comprehended by the latter_. For example, this speech, _man is a living creature_, in which two names are copulated by the verb _is_, is a _proposition_, for this reason, that he that speaks it conceives both _living creature_ and _man_ to be names of the same thing, or that the former name, _man_, is comprehended by the latter name, _living creature_. Now the former name is commonly called the _subject_, or _antecedent_, or the _contained name_, and the latter _predicate_, _consequent_, or _containing name_. The sign of connection amongst most nations is either some word, as the word _is_ in the proposition _man is a living creature_, or some case or termination of a word, as in this proposition, _man walketh_ (which is equivalent to this, _man is walking_); the termination by which it is said he _walketh_, rather than he _is walking_, signifieth that those two are understood to be copulated, or to be names of the same thing.

But there are, or certainly may be, some nations that have no word which answers to our verb _is_, who nevertheless form propositions by the position only of one name after another, as if instead of _man is a living creature_, it should be said _man a living creature_; for the very order of the names may sufficiently show their connection; and they are as apt and useful in philosophy, as if they were copulated by the verb _is_.

[Sidenote: Subject, predicate, and copula, what they are, and abstract and concrete what.]

3. Wherefore, in every proposition three things are to be considered, _viz._ the two names, which are the _subject_, and the _predicate_, and their _copulation_; both which names raise in our mind the thought of one and the same thing; but the copulation makes us think of the cause for which those names were imposed on that thing. As, for example, when we say _a body is moveable_, though we conceive the same thing to be designed by both those names, yet our mind rests not there, but searches farther what it is _to be a body_, or _to be moveable_, that is, wherein consists the difference betwixt these and other things, for which these are so called, others are not so called. They, therefore, that seek what it is _to be_ any thing, as _to be moveable_, _to be hot_, _&c._ seek in things the causes of their names.

And from hence arises that distinction of names (touched in the last chapter) into _concrete_ and _abstract_. For _concrete_ is the name of any thing which we suppose to have a being, and is therefore called the _subject_, in Latin _suppositum_, and in Greek ὑποκέιμενον; as _body_, _moveable_, _moved_, _figurate_, _a cubit high_, _hot_, _cold_, _like_, _equal_, _Appius_, _Lentulus_, and the like; and, _abstract_ is that which in any subject denotes the cause of the concrete name, as _to be a body_, _to be moveable_, _to be moved_, _to be figurate_, _to be of such quantity_, _to be hot_, _to be cold_, _to be like_, _to be equal_, _to be Appius_, _to be Lentulus_, _&c._ Or names equivalent to these, which are most commonly called _abstract_ names, as _corporiety_, _mobility_, _motion_, _figure_, _quantity_, _heat_, _cold_, _likeness_, _equality_, and (as Cicero has it) _Appiety_ and _Lentulity_. Of the same kind also are infinitives; for _to live_ and _to move_ are the same with _life_ and _motion_, or _to be living_ and _to be moved_. But _abstract names_ denote only the causes of _concrete names_, and not the things themselves. For example, when we see any thing, or conceive in our mind any visible thing, that thing appears to us, or is conceived by us, not in one point, but as having parts distant from one another, that is, as being extended and filling some space. Seeing therefore we call the thing so conceived _body_, the cause of that name is, that that thing is _extended_, or the _extension_ or _corporiety_ of it. So when we see a thing appear sometimes here, sometimes there, and call it _moved_ or _removed_, the cause of that name is that it _is moved_ or the _motion_ of the same.

And these causes of names are the same with the causes of our conceptions, namely, some power of action, or affection of the thing conceived, which some call the manner by which any thing works upon our senses, but by most men they are called _accidents_; I say accidents, not in that sense in which accident is opposed to necessary; but so, as being neither the things themselves, nor parts thereof, do nevertheless accompany the things in such manner, that (saving extension) they may all perish, and be destroyed, but can never be abstracted.

[Sidenote: The use and abuse of names abstract.]

4. There is also this difference betwixt _concrete_ and _abstract_ names, that those were invented before propositions, but these after; for these could have no being till there were propositions, from whose _copula_ they proceed. Now in all matters that concern this life, but chiefly in philosophy, there is both great use and great abuse of _abstract names_; and the use consists in this, that without them we cannot, for the most part, either reason, or compute the properties of bodies; for when we would multiply, divide, add, or substract heat, light, or motion, if we should double or add them together by concrete names, saying (for example) hot is double to hot, light double to light, or moved double to moved, we should not double the properties, but the bodies themselves that are hot, light, moved, &c. which we would not do. But the abuse proceeds from this, that some men seeing they can consider, that is (as I said before) bring into account the increasings and decreasings of quantity, heat and other accidents, without considering their bodies or subjects (which they call _abstracting_, or making to exist apart by themselves) they speak of accidents, as if they might be separated from all bodies. And from hence proceed the gross errors of writers of metaphysics; for, because they can consider thought without the consideration of body, they infer there is no need of a thinking-body; and because quantity may be considered without considering body, they think also that quantity may be without body, and body without quantity; and that a body has quantity by the addition of quantity to it. From the same fountain spring those insignificant words, _abstract substance_, _separated essence_, and the like; as also that confusion of words derived from the Latin verb _est_, as _essence_, _essentiality_, _entity_, _entitative_; besides _reality_, _aliquiddity_, _quiddity_, _&c._ which could never have been heard of among such nations as do not copulate their names by the verb _is_, but by adjective verbs, as runneth, readeth, &c. or by the mere placing of one name after another; and yet seeing such nations compute and reason, it is evident that philosophy has no need of those words _essence_, _entity_, and other the like barbarous terms.

[Sidenote: Proposition, universal and particular.]

5. There are many distinctions of propositions, whereof the first is, that some are _universal_, others _particular_, others _indefinite_, and others _singular_; and this is commonly called the distinction of _quantity_. An _universal_ proposition is that whose subject is affected with the sign of an universal name, as _every man is a living creature_. _Particular_, that whose subject is affected with the sign of a particular name, as _some man is learned_. An _indefinite_ proposition has for its subject a common name, and put without any sign, as _man is a living creature_, _man is learned_. And a _singular_ proposition is that whose subject is a singular name, as _Socrates is a philosopher_, _this man is black_.

[Sidenote: Affirmative and negative.]

6. The second distinction is into _affirmative_ and _negative_, and is called the distinction of _quality_. An _affirmative_ proposition is that whose predicate is a positive name, as _man is a living creature_. _Negative_, that whose predicate is a negative name, as _man is not a stone_.

[Sidenote: True & false.]

7. The third distinction is, that one is _true_, another _false_. A _true_ proposition is that, whose predicate contains, or comprehends its subject, or whose predicate is the name of every thing, of which the subject is the name; as _man is a living creature_ is therefore a true proposition, because whatsoever is called _man_, the same is also called _living creature_; and _some man is sick_, is true, because _sick_ is the name of _some man_. That which is not true, or that whose predicate does not contain its subject, is called a _false_ proposition, as _man is a stone_.

Now these words _true_, _truth_, and _true proposition_, are equivalent to one another; for truth consists in speech, and not in the things spoken of; and though _true_ be sometimes opposed to _apparent_ or _feigned_, yet it is always to be referred to the truth of proposition; for the image of a man in a glass, or a ghost, is therefore denied to be a very man, because this proposition, _a ghost is a man_, is not true; for it cannot be denied but that a ghost is a very ghost. And therefore truth or verity is not any affection of the thing, but of the proposition concerning it. As for that which the writers of metaphysics say, that _a thing_, _one thing_, and _a very thing_, are equivalent to one another, it is but trifling and childish; for who does not know, that _a man_, _one man_, and _a very man_, signify the same.

[Sidenote: True & false belongs to speech, and not to things.]

8. And from hence it is evident, that truth and falsity have no place but amongst such living creatures as use speech. For though some brute creatures, looking upon the image of a man in a glass, may be affected with it, as if it were the man himself, and for this reason fear it or fawn upon it in vain; yet they do not apprehend it as true or false, but only as like; and in this they are not deceived. Wherefore, as men owe all their true ratiocination to the right understanding of speech; so also they owe their errors to the misunderstanding of the same; and as all the ornaments of philosophy proceed only from man, so from man also is derived the ugly absurdity of false opinions. For speech has something in it like to a spider's web, (as it was said of old of _Solon's_ laws) for by contexture of words tender and delicate wits are ensnared and stopped; but strong wits break easily through them.

From hence also this may be deduced, that the first truths were arbitrarily made by those that first of all imposed names upon things, or received them from the imposition of others. For it is true (for example) that _man is a living creature_, but it is for this reason, that it pleased men to impose both those names on the same thing.

[Sidenote: Proposition, primary, not primary, definition, axiom, petition.]

9. Fourthly, propositions are distinguished into _primary_ and _not primary_. _Primary_ is that wherein the subject is explicated by a predicate of many names, as _man is a body_, _animated_, _rational_; for that which is comprehended in the name _man_, is more largely expressed in the names _body_, _animated_, and _rational_, joined together; and it is called _primary_, because it is first in ratiocination; for nothing can be proved, without understanding first the name of the thing in question. Now _primary_ propositions are nothing but definitions, or parts of definitions, and these only are the principles of demonstration, being truths constituted arbitrarily by the inventors of speech, and therefore not to be demonstrated. To these propositions, some have added others, which they call _primary_ and _principles_, namely, _axioms_, and _common notions_; which, (though they be so evident that they need no proof) yet, because they may be proved, are not truly principles; and the less to be received for such, in regard propositions not intelligible, and sometimes manifestly false, are thrust on us under the name of _principles_ by the clamour of men, who obtrude for evident to others, all that they themselves think true. Also certain petitions are commonly received into the number of principles; as, for example, _that a straight line may be drawn between two points_, and other petitions of the writers of geometry; and these are indeed the principles of art or construction, but not of science and demonstration.

[Sidenote: Proposition necessary & contingent.]

10. Fifthly, propositions are distinguished into _necessary_, that is, necessarily true; and true, but not necessarily, which they call _contingent_. A _necessary_ proposition is when nothing can at any time be conceived or feigned, whereof the subject is the name, but the predicate also is the name of the same thing; as _man is a living creature_ is a necessary proposition, because at what time soever we suppose the name _man_ agrees with any thing, at that time the name _living-creature_ also agrees with the same. But a _contingent_ proposition is that, which at one time may be true, at another time false; as _every crow is black_; which may perhaps be true now, but false hereafter. Again, in every _necessary_ proposition, the predicate is either equivalent to the subject, as in this, _man is a rational living creature_; or part of an equivalent name, as in this, _man is a living creature_, for the name _rational-living-creature_, or _man_, is compounded of these two, _rational_ and _living-creature_. But in a _contingent_ proposition this cannot be; for though this were true, _every man is a liar_, yet because the word _liar_ is no part of a compounded name equivalent to the name _man_, that proposition is not to be called _necessary_, but _contingent_, though it should happen to be true always. And therefore those propositions only are _necessary_, which are of sempiternal truth, that is, true at all times. From hence also it is manifest, that truth adheres not to things, but to speech only, for some truths are eternal; for it will be eternally true, _if man, then living-creature_; but that any _man_, or _living-creature_, should exist eternally, is not necessary.

[Sidenote: Categorical & hypothetical.]

11. A sixth distinction of propositions is into _categorical_ and _hypothetical_. A _categorical_ proposition is that which is simply or absolutely pronounced, as _every man is a living-creature_, _no man is a tree_; and _hypothetical_ is that which is pronounced conditionally, as, _if any thing be a man, the same is also a living-creature_, _if anything be a man, the same is also not-a-stone_.

A _categorical_ proposition, and an _hypothetical_ answering it, do both signify the same, if the propositions be necessary; but not if they be contingent. For example, if this, _every man is a living-creature_, be true, this also will be true, _if any thing be a man, the same is also a living-creature_; but in contingent propositions, though this be true, _every crow is black_, yet this, _if any thing be a crow, the same is black_, is false. But an _hypothetical_ proposition is then rightly said to be true, when the consequence is true, as _every man is a living-creature_, is rightly said to be a true proposition, because of whatsoever it is truly said _that is a man_, it cannot but be truly said also, _the same is a living creature_. And therefore whensoever an _hypothetical_ proposition is true, the _categorical_ answering it, is not only true, but also necessary; which I thought worth the noting, as an argument, that philosophers may in most things reason more solidly by _hypothetical_ than _categorical_ propositions.

[Sidenote: The same proposition diversely pronounced.]

12. But seeing every proposition may be, and uses to be, pronounced and written in many forms, and we are obliged to speak in the same manner as most men speak, yet they that learn philosophy from masters, had need to take heed they be not deceived by the variety of expressions. And therefore, whensoever they meet with any obscure proposition, they ought to reduce it to its most simple and categorical form; in which the copulative word _is_ must be expressed by itself, and not mingled in any manner either with the subject or predicate, both which must be separated and clearly distinguished one from another. For example, if this proposition, _man can not sin_, be compared with this, _man cannot sin_, their difference will easily appear if they be reduced to these, _man is able not to sin_, and, _man is not able to sin_, where the predicates are manifestly different. But they ought to do this silently by themselves, or betwixt them and their masters only; for it will be thought both ridiculous and absurd, for a man to use such language publicly. Being therefore to speak of _equipollent_ propositions, I put in the first place all those for _equipollent_, that may be reduced purely to one and the same categorical proposition.

[Sidenote: Propositions that may be reduced to the same categorical proposition, are equipollent.]

13. Secondly, that which is categorical and necessary, is _equipollent_ to its hypothetical proposition; as this categorical, _a right-lined triangle has its three angles equal to two right angles_, to this hypothetical, _if any figure be a right-lined triangle, the three angles of it are equal to two right angles_.

[Sidenote: Universal propositions converted by contradictory names, are equipollent.]

14. Also, any two universal propositions, of which the terms of the one (that is, the subject and predicate) are to the terms of the other, and their order inverted, as these, _every man is a living creature_, and _every thing that is not a living-creature is not a man_, are _equipollent_. For seeing _every man is a living creature_ is a true proposition, the name _living creature_ contains the name _man_; but they are both positive names, and therefore (by the last article of the precedent chapter) the negative name _not man_, contains the negative name _not living-creature_; wherefore _every thing that is not a living-creature, is not a man_, is a true proposition. Likewise these, _no man is a tree_, _no tree is a man_, are _equipollent_. For if it be true that _tree_ is not the name of any _man_, then no one thing can be signified by the two names _man_ and _tree_, wherefore _no tree is a man_ is a true proposition. Also to this, _whatsoever is not a living-creature is not a man_, where both the terms are negative, this other proposition is equipollent, _only a living creature is a man_.

[Sidenote: Negative propositions are the same, whether the negation be before or after the copula.]

15. Fourthly, negative propositions, whether the particle of negation be set after the copula as some nations do, or before it, as it is in Latin and Greek, if the terms be the same, are equipollent: as, for example, _man is not a tree_, and, _man is not-a-tree_, are equipollent, though Aristotle deny it. Also these, _every man is not a tree_, and _no man is a tree_, are equipollent, and that so manifestly, as it needs not be demonstrated.

[Sidenote: Particular propositions simply converted, are equipollent.]

16. Lastly, all particular propositions that have their terms inverted, as these, _some man is blind, some blind thing is a man_, are equipollent; for either of the two names, is the name of some one and the same man; and therefore in which soever of the two orders they be connected, they signify the same truth.

[Sidenote: What are subaltern, contrary, subcontrary, and contradictory propositions.]

17. Of propositions that have the same terms, and are placed in the same order, but varied either by quantity or quality, some are called _subaltern_, others _contrary_, others _subcontrary_, and others _contradictory_.

_Subaltern_, are universal and particular propositions of the same quality; as, _every man is a living creature_, _some man is a living creature_; or, _no man is wise_, _some man is not wise_. Of these, if the universal be true, the particular will be true also.

_Contrary_, are universal propositions of different quality; as, _every man is happy_, _no man is happy_. And of these, if one be true, the other is false: also, they may both be false, as in the example given.

_Subcontrary_, are particular propositions of different quality; as, _some man is learned_, _some man is not learned_; which cannot be both false, but they may be both true.

_Contradictory_ are those that differ both in quantity and quality; as, _every man is a living creature_, _some man is not a living-creature_; which can neither be both true, nor both false.

[Sidenote: Consequence, what it is.]

18. A proposition is said to _follow_ from two other propositions, when these being granted to be true, it cannot be denied but the other is true also. For example, let these two propositions, _every man is a living creature_, and, _every living creature is a body_, be supposed true, that is, that _body_ is the name of _every living creature_, and _living creature_ the name of _every man_. Seeing therefore, if these be understood to be true, it cannot be understood that _body_ is not the name of _every man_, that is, that _every man is a body_ is false, this proposition will be said to _follow_ from those two, or to be necessarily _inferred_ from them.

[Sidenote: Falsity cannot follow from truth.]

19. That a true proposition may follow from false propositions, may happen sometimes; but false from true, never. For if these, _every man is a stone_, and _every stone is a living creature_, (which are both false) be granted to be true, it is granted also that _living creature_ is the name of _every stone_, and _stone_ of _every man_, that is, that _living creature_ is the name of _every man_; that is to say, this proposition _every man is a living creature_, is true, as it is indeed true. Wherefore a true proposition may sometimes follow from false. But if any two propositions be true, a false one can never follow from them. For if true follow from false, for this reason only, that the false are granted to be true, then truth from two truths granted will follow in the same manner.

[Sidenote: How one proposition is the cause of another.]

20. Now, seeing none but a true proposition will follow from true, and that the understanding of two propositions to be true, is the cause of understanding that also to be true which is deduced from them; the two antecedent propositions are commonly called the causes of the inferred proposition, or conclusion. And from hence it is that logicians say, the _premises_ are causes of the _conclusion_; which may pass, though it be not properly spoken; for though understanding be the cause of understanding, yet speech is not the cause of speech. But when they say, the cause of the properties of any thing, is the thing itself, they speak absurdly. For example, if a figure be propounded which is triangular; seeing every triangle has all its angles together equal to two right angles, from whence it follows that all the angles of that figure are equal to two right angles, they say, for this reason, that that figure is the cause of that equality. But seeing the figure does not itself make its angles, and therefore cannot be said to be the _efficient-cause_, they call it the _formal-cause_; whereas indeed it is no cause at all; nor does the property of any figure follow the figure, but has its being at the same time with it; only the knowledge of the figure goes before the knowledge of the properties; and one knowledge is truly the cause of another knowledge, namely the _efficient cause_.

And thus much concerning _proposition_; which in the progress of philosophy is the first step, like the moving towards of one foot. By the due addition of another step I shall proceed to _syllogism_, and make a complete pace. Of which in the next chapter.

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