Authors/Ockham/Summa Logicae/Book III-2/Chapter 3

Latin	English
CAP. 3. QUAE OPORTET DEMONSTRANTEM PRAECOGNOSCERE?.	CHAPTER 3 What does a demonstrator have to cognize beforehand?
Non tantum autem oportet istos terminos ad demonstrationem concurrere, sed etiam quandocumque demonstrationem ingrediuntur, antequam conclusio concludatur oportet eos praecognoscere, non tamen oportet illos semper aequaliter praecognoscere.	Now, not only do these terms have to come together for demonstration, but also, whenever they are involved in a demonstration, we must cognize them beforehand before the conclusion is drawn. Yet we do not always have to cognize them beforehand equally.
De subiecto enim oportet praecognoscere quid est et quia est.	For concerning the subject we have to cognize beforehand ‘what it is’ [quid est] and ‘that it is’ (quia est).
Oportet enim de subiecto, cum sit terminus, praecognoscere quid significat; et haec praecognitio communis est omni termino cuiuscumque syllogismi vel argumentationis.	For since the subject is a term, we must cognize beforehand what it signifies; and this cognition beforehand is common to every term of any syllogism or argument.
Si autem sit demonstratio affirmativa et categorica, non oportet tantum de subiecto praecognoscere quid significat, sed etiam oportet praecognoscere quia est; hoc est, oportet praecognoscere quod esse non impossibiliter praedicatur de subiecto significative sumpto.	But if it is an affirmative and categorical demonstration, we not only have to cognize beforehand concerning the subject what it signifies, but we also have to cognize beforehand that it is, i.e., we have to cognize beforehand that being is not predicated impossibly of a subject taken significatively.
Et ratio huius est, quia ad hoc quod habeatur demonstratio, oportet quod praemissae cognoscantur; igitur oportet quod illa praemissa in qua praedicatur aliquid de subiecto, vel e converso, sit cognita, et per consequens vera est.	And the reason for this is that in order to have a demonstration, the premises have to be cognized; therefore it has to be that the premise in which something is predicated of the subject, or vice versa, is cognized, and consequently [it has to be that] the premise is true.
Et si sit vera et scita esse vera, oportet quod sibi non impossibiliter competat esse, ex quo propositio est affirmativa.	And if it is true, and is known to be true, it is necessary that being is not appropriated impossibly with the subject, from which the proposition is affirmative.
De passione autem, quamvis ingrediatur demonstrationem affirmativam, non oportet praecognoscere nisi tantum quid importatur per nomen, sed non oportet quod praecognoscatur quod sibi non repugnat esse.	But concerning the attribute, even if it be contained in an affirmative demonstration we do not have to cognize beforehand anything except what is conveyed by the name, but it is not necessary that it be cognized beforehand that being is not repugnant to it.
Et hoc quidem verum est si maior illius demonstrationis sit condicionalis vel aequivalens tali; tunc enim non oportet --- quantumcumque ƿ cognoscatur illa praemissa in qua ponitur passio --- quod cognoscatur esse posse convenire passioni.	And this is true, of course, if the major premise of the demonstration is conditional or equivalent to such [a conditional], for then it does not have to be - however much that premise in which the attribute is given is cognized— that it be cognized that being is able to agree with the attribute.
Quando autem maior est affirmativa, non aequivalens condicionali, ita oportet praecognoscere de passione quia est sicut de subiecto. Nec hoc negat Aristoteles, sed vult quod quandoque oportet praecognoscere quia est de subiecto, quamvis non oporteat praecognoscere quia est de passione.	But when the major is affirmative, not equivalent to a conditional, so we have to cognize beforehand of the attribute that it is just as it is concerning the subject. Nor does Aristotle deny this, but he would have it that sometimes we have to cognize beforehand that it is concerning the subject, although we do not have to cognize beforehand that it is concerning the attribute.
Breviter igitur dicendum est quod secundum principia Aristotelis de subiecto in demonstratione affirmativa, tam categorica simpliciter quam in demonstratione composita ex una hypothetica condicionali et alia categorica, oportet praecognoscere de subiecto quid significat et quia est; hoc est, quod sibi non repugnat esse, ita quod propositio praedicans esse de illo subiecto non includat contradictionem.	Briefly, then, it must be said that according to Aristotle's principles about the subject in affirmative demonstration, both in demonstrations that are absolutely categorical and in demonstrations composed from a hypothetical conditional and a categorical premise, we have to cognize beforehand concerning the subject what it signifies and that it is, i.e., that being is not repugnant to it, so that a proposition predicating being of that subject does not involve a contradiction.
De passione autem in demonstratione simpliciter categorica et affirmativa oportet praecognoscere tam quia est quam quid est, propter eandem rationem propter quam oportet de subiecto praecognoscere quia est; sed in alia demonstratione non oportet de passione praecognoscere quia est.	But concerning the attribute in an affirmative demonstration that is categorical without qualification we have to cognize beforehand that it is as well as what it is, and this for the same reason that we have to cognize beforehand concerning the subject that it is. But in other [sorts of] demonstration we do not have to cognize, concerning the attribute, that it is.
De definitione autem oportet praecognoscere quia est, propter eandem rationem propter quam oportet de subiecto praecognoscere quia est. Et haec de terminis demonstrationis ad praesens sufficiant.	But concerning definition we have to cognize beforehand that it is for the same reason we have to cognize beforehand concerning the subject that it is. And this is sufficient at present for the terms of demonstration.