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

Latin	English
ƿ CAP. 2. QUI TERMINI INGREDIUNTUR DEMONSTRATIONEM?.	CHAPTER 2 What terms are included in a demonstration?
Ex quo omnis demonstratio est syllogismus, necesse est omnem demonstrationem tres terminos ad eius constitutionem requirere. Non omnes autem termini possunt ingredi demonstrationem affirmativam ex propositionibus mere de inesse et mere de praesenti. Illi enim termini qui de nullo possunt praedicari nisi contingenter vel falso, ipsis sumptis significative, numquam possunt significative sumpti esse partes demonstrationis talis.	From the fact that every demonstration is a syllogism, it is necessary that every demonstration requires three terms in its constitution. But not all terms can be included in an affirmative demonstration made up from propositions purely assertoric (de inesse) and purely in the present tense. For those terms that be predicated of nothing except contingently or falsely, when they are taken significatively, can never be taken significatively taken to be parts of such a demonstration.
Et ideo tales termini ‘chimaera’, ‘corpus [infini]tum’, ‘creatura infinita’ et huiusmodi non possunt, si significative sumantur, esse termini in demonstratione tali, quamvis possint in demonstratione negativa, quia etiam negative possunt de aliis necessario praedicari.	And therefore such terms as "chimera" "infinite body" "infinite creature" and the like, if they are taken significatively, cannot be terms in such a demonstration, although they could be in a negative demonstration—for they can also be predicated necessarily of other things negatively.
Similiter, quamvis tales termini ‘album’, ‘nigrum’, ‘calidum’ et huiusmodi non possint esse partes propositionum necessariarum mere de inesse et mere de praesenti affirmativarum, quia tamen possunt esse partes propositionum de possibili necessariarum, ideo tales demonstrationem ingredi possunt.	Similarly, although such terms as "white " "black " "hot," and the like could not be parts of necessary affirmative propositions, purely assertoric and purely present tense, such terms can be included in demonstration because they can still be parts of necessary propositions de possibile [check].
Unde breviter, secundum diversitatem demonstrationum, de qua dicetur inferius, omnes termini aliquam demonstrationem ingredi possunt; sed non omnes ingredi possunt demonstrationem potissimam, de qua inferius dicetur.	Briefly therefore, according to the diversity of demonstrations, which we will talk about below, all terms can be included in some demonstration; but not all terms can be included in the highest sort of demonstration, which we will talk about below.
Termini autem illi qui demonstrationem potissimam ingredi possunt, sunt praecise subiectum, passio et definitio. Ad cuius evidentiam sciendum est quod passio non est aliqua res inhaerens subiecto, illo modo quo calor inest igni, sed passio est quoddam praedicabile, distinctum a subiecto, et realiter importans illud idem quod [importat/important] subiectum et aliquid plus, vel saltem illud idem alio modo.	Now those terms that can be included in the highest sort of demonstration are precisely: subject, attribute, and definition For evidence of which, you should know that an attribute [passio] is not some reality inhering in a subject, in the way that heat inheres in fire, but an attribute is a certain predicable, distinct from the subject, and really conveying the same thing that the subject conveys, and also something more, or at least, if the same, in a different way.
Et eodem modo est de definitione: ut isti termini ex quibus componitur demonstratio mentalis sint ita distinctae res exsistentes in mente ƿ sicut voces correspondentes eis in demonstratione vocali sunt distinctae voces in aere, de quibus diffusius dicetur inferius.	And it is the same way with definition, so that those terms from which a mental demonstration is composed are distinct realities existing in the mind, just as utterances corresponding to them in a vocal demonstration are distinct utterances in the air. (Of which more detail below)