Authors/Ockham/Summa Logicae/Book III-2/Chapter 1

GUILLELMI DE OCKHAM SUMMA TOTIUS LOGICAE: PARS III-2

Latin	English
CAP. 1. QUID INTELLIGITUR PER HUNC TERMINUM ‘DEMONSTRATIO’ ET QUOT MODIS DICITUR ‘SCIRE’?.	What is understood by the term "demonstration," and in how many ways is "to know" predicated?
Postquam dictum est de syllogismo in communi, sequitur nunc tractare de speciebus syllogismi. Et quia nobilior est demonstratio, ideo primo de demonstratione oportet dicere. Omnis autem demonstratio componitur ex propositionibus et propositiones ex terminis. Unde, quia terminorum et propositionum ex quibus constat demonstratio sunt quaedam condiciones propriae, non omnibus terminis et propositionibus competentes, ideo primo dicendum est de terminis et condicionibus eorum, secundo de propositionibus requisitis ad demonstrationem, tertio de demonstratione.	Now that we have discussed the syllogism in general, it follows now that we deal with the species of syllogism. And since demonstration is more noble, therefore we have to speak of it first. Now every demonstration is composed from propositions, and propositions from terms. Therefore, because there are certain conditions proper to the terms and propositions from which demonstration is constituted, which do not belong to all terms and propositions, we must therefore speak first of their terms and conditions, secondly of the propositions required for demonstration, and thirdly of demonstration itself.
Oportet autem in principio scire quod, secundum doctrinam Aristotelis, demonstratio est syllogismus faciens scire. Ista enim definitio ‘syllogismus faciens scire’ est definitio exprimens quid nominis istius termini ‘demonstratio’.	But you should know to begin with that, according to Aristotle's teaching, a demonstration is ‘a syllogism that produces knowing’ [scire]. For this definition, "syllogism that produces knowing," is a definition expressing the nominal essence [quid nominis] of the term "demonstration."
Et ideo sicut in omni disputatione et veritatis inquisitione oportet significata vocabulorum supponere, ita volenti tradere notitiam demonstrationis et partium suarum oportet praemittere quid per hunc terminum ‘demonstratio’ importatur.	And therefore, just as it is necessary in every disputation and inquiry after truth to presuppose the significates of the words, so the person wishing to hand on knowledge [notitia] of demonstration and its parts has to say first what is conveyed by the term "demonstration."
Quod non est aliud quam definitionem exprimentem quid nominis declarare.
Dico igitur quod omnes de demonstratione loquentes per hunc terminum ‘demonstratio’ non intelligunt nisi syllogismum facientem scireƿ. Sed quia ‘scire’ in diversis locis aequivoce accipitur, videndum est quomodo ‘scire’ in hac definitione accipitur.	I say therefore that all who speak of demonstration by the term "demonstration" understand nothing but a syllogism producing knowing. But since "knowing" is taken equivocally in diverse places, we must see in what way "knowing" is taken in this definition.
Unde sciendum est quod quamvis ‘scire’ diversis modis accipi possit, sufficiat tamen ad praesens dicere quod tribus modis dicitur. Uno modo ‘scire’ est evidens comprehensio veritatis. Et sic dicuntur sciri non tantum necessaria sed etiam contingentia, sicut ‘scio te sedere’ et ‘scio me intelligere et vivere’.	Hence you should know that although "knowing" can be taken in diverse ways, nonetheless it is sufficient for the present to say that it is meant in three ways. In one way, knowing is evident comprehension of the truth, and thus not only necessary things but also contingent things are said to be known. For instance, "I know that you are sitting" and "I know that I understand and am alive" .
Secundo modo dicitur scientia evidens comprehensio veritatis quae non potest esse falsa. Et sic dicuntur sciri tantum necessaria et non contingentia.	In the second way, evident comprehension of truth that cannot be false is called knowledge. And thus only necessary things (and not contingent things) are said to be known.
Tertio modo dicitur scientia evidens comprehensio unius veritatis necessariae per evidentem comprehensionem duarum veritatum necessariarum, in modo et figura dispositarum, ut illae duae veritates faciant tertiam veritatem evidenter sciri, quae aliter esset ignota.	In the third way, evident grasp of a necessary truth through the evident grasp of two other necessary truths disposed in figure and mood - so that these two truths make a third truth evidently known which would otherwise be unknown. - is called knowledge.
Et sic accipitur ‘scire’ in praedicta definitione. Omnes enim recte loquentes de demonstratione per demonstrationem intelligunt syllogismum compositum ex duabus praemissis necessariis notis, per quas scitur conclusio quae aliter foret ignota, nisi forte in eodem tempore simul concurrant cum illis praemissis aliae praemissae sufficientes ad causandum notitiam eiusdem conclusionis.	And thus "knowing" is taken in the definition above. For all who speak correctly of demonstration understand by "demonstration" a syllogism composed from two necessary premises that are known, through which a conclusion is known that would otherwise be unknown. Unless, perhaps, other premises sufficient for producing knowledge [notitiam] of the conclusion occur together with these at the same time.
Quamvis igitur probari non possit quod demonstratio est syllogismus faciens scire, modo praeexposito, sicut nec significatum vocabuli nec definitio exprimens quid nominis probari potest nisi per usum loquentium, constituendum est tamen pro fundamento quod demonstratio est syllogismus faciens scire, super quo omnia dicenda in sequentibus fundabuntur, et per ipsum probabuntur quando necesse erit probationem adducere.	Therefore, although it cannot be proved that demonstration is a syllogism producing knowing in the way expressed above (just as neither the significate of a word nor a definition expressing nominal essence can be proved except by the usage of speakers), nevertheless it must be established as a basic principle [fundamento] that demonstration is a syllogism producing knowing, upon which all the things to be said in what follows will be based. And what is said in the following [sections] will be proved using this [basic principle] whenever it is necessary to cite a proof.