The Elements of Logic, Book 3

The Elements of Logic · Book 3

p. 105¶ The third Booke. Of ENVNTIATION.

The firſt Chapter. What an Enuntiation is, and the parts thereof.

THE places or helpes of invention contained in the ſixteene precedent Chapters, afford vntounto vsus abundan… … …ter for proofes and arguments. I… n…w remaineth that we giuegive a forme vntounto theſe proofes or arguments, and ſhew how to frame an argument, ſo as it may be of force to proue.

An argument or reaſoning is by the Philoſophers called a Syllogiſme; p. 106which is a Grecke word ſignifying the making vp of an account, or the collecting of a ſumme. For that which is the making vp of an account, or the totall ſumme of Additiō or Multiplication in Arithmetick, the ſame is the concluſion in a Syllogiſme, namely, that which reſulteth and followeth from the proofe.

Every Syllogiſme is compoſed of two Propoſitions or Enuntiations, and of a Concluſion.

Enuntiation is a ſpeech, wherein ſomething is affirmed or denied.

Every Enuntiation conſiſts of two words at the leaſt, which the Logicians call Termes: as, who would ſay, the two ends, or the two peeces. For example.

The fire burneth.

God is good.

Theſe Enuntiations are compounded of two parts, the one is called the Subject; the other, the Attribute. Fire is the Subject; and burneth is the Attribute; For burning is attributed to fire. God is the Subject; and this word good is the Attribute.

p. 107This Verb, Is, is not reckoned as a part of the Enuntiation, but is onelyonly the linke and bond of theſe two parts.

Whereſoever there is an affirmation or negation, there is an Enuntiation, though it ſeemeth to be but one word. As when we ſay in Latin, Curro, we vnderſtand, ego curro, I runne. And in Engliſh, It raineth, is an vſuall and common word, which is as much as this Enuntiation, the raine falleth. So when we ſay, It freezeth, It ſnoweth, &c.

And when wee aske any body, Sleepe you? He that anſwereth No, maketh a kinde of ſecret Enuntiation; for it is as much as if he ſhould ſay, I ſleepe not.

When we argue, the Enuntiations muſt be full and perfect, ſo as there may be no need of any ſupplying.

All truth and falſhood is expreſſed by the Indicatiue mood; and therefore every Enuntiation muſt be couched in the Indicatiue; becauſe wee affirme or deny a thing onelyonly by that p. 108mood. And therefore Imperatiues, Optatiues and Subiunctiues enter not into an E…untiation, nor doe any …ervice to the Art of Logick, who…e end and ſcope is to ſearch out and diſcerne the truth. Now t…uth is onelyonly expreſſed …y the In…icatiue. The other moods are left to Rhetorick, and ſerue onelyonly for ornament.

Sometimes one of the… termes or parts of the Enuntiation is expreſſed by many words; as,

All the lines drawne from the center to the circumference of the circle are equall.

God is free from all infirmitie.

The Verb Subſtantiue is th… …ch cauſeth the Subject to be …ed from the A…tribute; for … between both.

An Enuntiation and a Propoſition are the ſame thing; yet out of a Syll…giſme we… call it Enuntiation, but in a Syllogiſme wee call it Propoſition.

p. 109The ſecond Chapter. Of the kinds of Enuntiation.

ENuntiations are either Simple or Compounded.

The Simple Enuntiatiō, which alſo is called Categoricall, when a thing is affirmed or denied ſimply & without condition, and without adding a Whether, or an If; as,

Man is reaſonable.

Heaven is round.

Water is colde.

God is no lyar.

Of theſe Enuntiations ſome are Vniverſall, and ſome particular.

Vniverſall Enuntiations are ſuch as hauehave theſe words, All, or None, joyned with them. As,

All men are ſinners.

No man is perfect.

Particular Enuntiations are ſuch as doe not affirme or denie generally of all, but onelyonly of ſome in particular. As,

p. 110Some man is blacke.

Some Kings hauehave not beene wiſe.

Every horſe is not white.

VnderUnder particular Enuntiations, the Singulars are alſo comprehended: As,

Peter is fooliſh.

This man is a Philoſopher.

Enuntiations which hauehave no note whereby they may be diſcerned to be vniverſals or particulars, are called Indefinites, and in ſtrict dealing muſt be taken for particulars. Notwithſtanding, when the matter is Neceſſarie, they are of as much force as vniverſals. As when I ſay, Man is reaſonable, it is as much as if I ſhould ſay, All men are reaſonable.

But if the matter be contingent and and mutable: as, Man is white, they are but as particulars, and is no more then if I ſhould ſay, Some man is white.

Againe, Enuntiations are either Affirmatiue or Negatiue: Affirmatiue; as, God is good. Negatiue; as, God is no lyar.

p. 111Thus we ſee there are foure kinde of Enuntiations. For they are either Vniverſall Affirmatiues. As, All men are white. Or Vniverſall Negatiues, as, No man is white. Or Particular Affirmatiues, as, Some man is white. Or Particular Negatiues, as, Some man is not white.

The vniverſalitie or particularitie of an Enuntiation is called the quantitie thereof. But to be Affirmatiue or Negatiue maketh the qualitie.

Simple Enuntiations are ſometimes modified by certaine circumferences of Neceſſitie, or Contingency, or Poſſibilitie, or Impoſſibilitie; as,

It is neceſſary that man be reaſonable.

It falleth out that it thunders in Winter.

It is poſſible that it raineth or hath rained.

It is impoſſible that the Soule ſhould be mortall.

An Enuntiation thus modified or qualified by ſuch circumſtances is Negatiue, when the negation is joyned to the modification or circumſtance. p. 112As when we ſay, It is not neceſſarie that Caeſar overcome. But this Enuntiation, It is neceſſarie that Pompey overcome not, is affirmatiue.

Compounded Enuntiations are either Conditionall or Disjunctiue.

Conditionall Enuntiations are ſuch as neither affirme nor deny ſimply, but with an If; as,

If it be day, the Sunne is vp.

If God will, the troubles ſhall ceaſe.

Theſe Enuntiations are compounded of two parts; the former is called the Antecedent: and the latter the Conſequent. And both theſe may be affirmatiue; as, If it be day, the Sunne is vp.

Sometimes the one is affirmatiue, and the other negatiue; as, If the Sunne be not vp, it is night. or, If the Sunne be vp, it is not night.

And ſometimes both negatiues; as, If it be not a liuing creature, it is no man.

p. 113Disjoyned or Disjunctiue Enuntiations are ſuch as are compounded of oppoſed parts, whereof the one overthrowes the other; as, either,

It is day, or night.

This man is aliue, or dead.

Theſe Enuntiations are not true, except both parts be immediately contraries or oppoſits. For if I ſhould ſay, This cloake is blacke, or white, I might ſpeake againſt the truth; for the cloake may be gray or tawnie, &c.

The third Chapter. Of the Oppoſition of Enuntiations.

OF Enuntiations ſome are neceſſary, and ſome probable or contingent. According to this difference Enuntiations are more or leſſe oppoſit one to another. Neceſſarie Enuntiations are either when the Genus is attributed to the Species; as, Man is a liuing creature. Or the difference; p. 114as, Man is reaſonable. Or the propertie; as, All fire is hot. The Contingents are when ſome accident is attributed to the Subject; as, The horſe is white. Man is a Phyſician.

The Oppoſition of Enuntiations is done three manner of wayes. Either as Contraries, or Subcontraries, or Contradictories. In all which Oppoſitions one of the two oppoſed Enuntiations muſt ever be affirmatiue, and the other Negatiue, and the ſame termes muſt ſtill be kept.

Contrary Enuntiations are an vniverſall affirmatiue, and an vniverſall negatiue; as,

All men are iuſt.

No man is iuſt.

Which are both falſe, becauſe the matter is Contingent. But if the matter be Neceſſary, then the one is true, and the other falſe; as,

All men are liuing creatures.

No man is a liuing creature.

Subcontrarie Enuntiations are two particulars contained vnderunder two vniverſals, whereof the one affirmeth, p. 115and the other denieth; as,

Some man is iuſt,

Some man is not iuſt.

In a neceſſary matter the one is true, and the other falſe. But in a contingent matter they may both be true.

Contradictory Enuntiations are an vniverſall affirmatiue, and a particular negatiue. Or els an vniverſall negatiue, and a particular affirmatiue; as,

All men are white.

Some man is not white.

Or els.

No man is not white.

Some man is white.

Of theſe two Enuntiations it is neceſſary that the one be true, and the other falſe, in what matter ſoever it be.

Contraries agree in quantitie, but are oppoſit in qualitie; as alſo Sub-contraries: but Contradictories are both.

p. 116The Oppoſition of Enuntiations in matters Neceſſary.

The Oppoſition of Enuntiations in a matter Contingent.

p. 117Two ſingular Enuntiations cannot be oppoſed one to another, but Contradictorily; as, Peter is white. Peter is not white.

And therefore of neceſſitie the one muſt be true, and the other falſe.

The fourth Chapter. Of the Converſion of Enuntiations.

TO Convert an Enuntiation, is to change it ſo as that the ſubject is turned into the attribute, and the attribute into the ſubject, keeping ſtill the truth. As, No man is a horſe. Then if you will convert this Enuntiation, you muſt ſay, No horſe is a man.

This Converſion is done either Simply, or by Accident.

The Simple Converſion is, when the Enuntiation is changed without altering the quantitie. Thus are vniverſall negatiues converted; as in the example before mentioned.

And ſo are particular affirmatiues. p. 118As, Some man is learned, and, Some learned is a man.

But vniverſall affirmatiues cannot be converted Simply. For in turning them ſo, their truth would be loſt. Thus it is true, that, Every man is a living creature: but it is not true, that, Every liuing creature is a man.

Therefore when wee goe about to convert ſuch Propoſitions, wee take away their vniverſall quantitie, and in ſtead of ſaying Every man is a living creature, we turne it into a particular Enuntiation, & ſay, Some living creature is a man. Except when the ſubject is the ſpecies, & the attribute the property or differēce. For in this caſe the propoſition may bee converted ſimply. For example, All living creatures hauehave ſenſe; and, All, that hath ſenſe is a living creature. All bodies hauehave three dimenſions: All that hath three dimenſions is a bodie.

Particular negatiues are not converted: for example, this Enuntiation, Some man is not a Philoſopher, is true. But if you would turne it, it would p. 119proue falſe: Some Philoſopher is not a man.

Vniverſall affirmatiues may be converted into vniverſall negatiues, compoſed of two negations. As,

All men are living creatures.

Whatſoever is not a living creature is no man.

A ſingular affirmatiue may be converted into a particular affirmatiue. As, This horſe is lame: Some lame thing is a horſe.