Authors/Ockham/Summa Logicae/Book II/Chapter 8

Latin	English
[2.08 AD COGNOSCENDUM QUANDO PROPOSITIO CUIUS ALTERUM EXTREMUM EST TERMINUS OBLIQUUS FUERIT VERA VEL FALSA]	8: How to Find Out when a Proposition, One of Whose Extremes is in an Oblique Case, is True or False
Illa autem quae praedicta sunt non sufficiunt ad cognoscendum quando propositio cuius alterum extremum est terminus obliquus fuerit vera vel falsa, sed circa hoc oportet habere regulas speciales. Et sunt hic utiles regulae grammaticales de quibus tamen me breviter expediam.	Now the things said above are not sufficient for finding out when a proposition, one of whose extremes is an oblique term, will be true or false, but on this matter we will need special rules. And there are some useful grammatical rules here, which I will nonetheless quickly bring out.
Unde sciendum est quod sicut in propositione affirmativa, cuius uterque terminus est rectus, ad veritatem propositionis requiritur quod subiectum et praedicatum supponant pro eodem, ita nonnumquam ad veritatem propositionis, cuius alter terminus est obliquus, requiritur quod subiectum et praedicatum non supponant pro eodem, vel non pro omni eodem. Aliquando tamen possunt supponere pro eodem secundum diversitatem verborum et regiminis casus obliqui. Unde quando casus obliquus regitur ex vi possessionis, ad veritatem talis propositionis requiritur quod subiectum et praedicatum supponant pro distinctis, quamvis hoc non semper sufficiat. Ideo haec est falsa 'Sortes est Sortis', haec tamen poterit esse vera 'aliquis asinus est Sortis' -- Et sicut est in isto casu ita est in multis. Aliquando autem poterit propositio esse vera non obstante quod subiectum et praedicatum supponant pro eodem, sive non obstante quod rectus et obliquus supponant pro eodem; sicut haec est vera 'Sortes videt Sortem'. Et sic poterit contingere de multis aliis. Nec est facile in his regulam generalem et certam dare.	Hence you should know that just as in an affirmative proposition in which both terms are in the nominative case, it is required for the truth of the proposition that the subject and predicate supposit for the same thing, so too sometimes for the truth of a proposition in which one term is oblique, it is required that the subject and predicate do not supposit for the same thing or that they not supposit for all the same things. Still, sometimes they can supposit for the same thing according to the diversity of words and of the rule for an oblique case. Hence, when the oblique case is governed from force of possession, then for the truth of such a proposition it is required that the subject and predicate supposit for distinct things, although this is not always sufficient. Therefore, 'Socrates belongs to Socrates' is false, and yet 'Some donkey belongs to Socrates' can be true. And just as it is in this case, so it is with many. But sometimes the proposition will be able to be true despite the fact that the subject and predicate supposit for the same thing, or notwithstanding that the nominative term and the oblique term supposit for the same thing. For example, 'Socrates sees Socrates' is true. And the same thing can happen in many other cases. Nor is it easy to give a general and fixed rule.