Authors/Ockham/Summa Logicae/Book II/Chapter 35

Latin	English
[2.35 DE PROPOSITIONE TEMPORALI ET QUID REQUIRITUR AD VERITATEM EIUS]	On the temporal proposition, and what is required for the truth of it
Propositio temporalis est illa quae componitur ex pluribus categoricis mediante aliquo adverbio temporis. Sicut ista est temporalis 'Sortes currit, dum Plato disputat'; similiter ista 'Sortes fuit albus, quando Plato fuit niger'; similiter ista 'Sortes fuit albus, quando Plato non currebat'.	A temporal proposition is one composed of several categoricals with some intermediary adverb of time. For example, this is a temporal proposition: 'Socrates is running while Plato is disputing', likewise: 'Socrates was white when Plato was black', likewise 'Socrates was white when Plato was not running'.
Ad veritatem autem temporalis requiritur veritas utriusque partis pro eodem tempore vel pro diverso tempore. Unde aliqua sunt adverbia quae denotant propositiones quas coniugunt esse veras pro eadem tempore et aliqua pro diverso tempore. Unde ad veritatem istius 'Deus agit, quando creatura agit' requiritur quod utraque istarum sit vera et in eodem tempore. Similiter ad veritatem istius 'Apostoli praedicabant, dum Christus praedicavit' requiritur veritas utriusque partis et quod in eodem tempore fuerint verae, si fuerint formatae. Sed ad veritatem istius 'Paulus fuit conversus, postquam Christus fuit passus' requiritur quod istae propositiones fuerint verae pro diverso tempore; similiter ad veritatem istius 'Christus praedicavit, antequam patiebatur' requiritur quod ambae partes fuerunt verae pro diverso tempore.	Now for the truth of a temporal proposition it is required that both parts be true for the same time or for a different time. Hence, some adverbs denote that the propositions which they conjoin are true for the same time, and others which denote that they are true for a different time. Hence, for the truth of 'God acts when a creature acts' it is required that both parts be true, and at the same time. Likewise, for the truth of 'the apostles were preaching while Christ preached' there is required the truth of both parts and that they were true at the same time, if they were formed. But for the truth of 'Paul was converted after Christ had suffered' it is required that the propositions were true for a different time. Likewise, for the truth of 'Christ preached before he suffered' it is required that both parts were true for a different time.
Tamen sciendum est quod ad hoc quod temporalis sit vera, non requiritur quod numquam fuerint partes verae pro eodem tempore vel numquam pro diverso, sed quod aliquando fuerint verae pro eodem tempore vel pro diverso. Et ideo istae duae stant simul 'Apostoli praedicaverunt, dum Christus praedicavit' et 'Apostoli praedicaverunt postquam Christus praedicavit'.	Still, it should be known that for a temporal proposition to be true, it is not required that the parts were never true for the same time or that they were never true for a different time. Rather, it is required that they were sometimes true for the same time or for a different time. Hence, the following two propositions stand together: 'The apostles preached while Christ preached' and 'The apostles preached after Christ preached'.
Similiter ad necessitatem temporalis requiritur necessitas utriusque partis. Et ideo nulla talis est necessaria 'lignum calefit, quando ignis sibi approximatur'; 'creatura creatur, quando Deus creat'; 'asinus est risibilis, quando est homo'. Et si in aliquo auctore inveniantur tales propositiones et asserat eas esse necessarias, glossandae sunt tales: ut auctor non loquatur de virtute sermonis, sed per temporalem intelligit condicionalem, ut talis 'creatura creatur, quando Deus creat' importat istam 'si Deus creat, creatura creatur'.	Likewise, for the necessity of a temporal proposition it is required that each part be necessary. Hence, no proposition such as the following is necessary: 'wood becomes warm when fire is brought near it', 'a creature is created when God creates', 'a donkey is capable of laughter when it is a man'. And if in some author such propositions are found and he asserts that they are necessary, then they should be glossed, so that the author is not speaking literally, but through a temporal proposition understands a conditional, so that a proposition like 'a creature is created when God creates' conveys 'if God creates, a creature is created'.
Unde ista propositio 'Sortes est, dum est' vel 'Sortes movetur, dum currit' non est necessaria, sed poterit esse falsa. Verumtamen per tales temporales intelligunt condicionales, quae condicionales verae sunt.	Hence, the proposition 'Socrates exists while he exists' or 'Socrates moves while he runs' is not necessary, but could be false. Nevertheless, some understand such temporal propositions as conditionals, which conditionals are true.
Similiter, ad impossibilitatem temporalis non requiritur impossibilitas alicuius partis, sed sufficit quod partes sint incompossibiles. Unde ista est impossibilis 'Deus creat, dum non creat', quia partes sunt incompossibiles. Si autem sit temporalis quae notet propositiones esse veras pro diverso tempore, tunc ad hoc quod sit impossibilis, sufficit quod partes sint convertibiles, ita quod una non possit esse vera sine alia nec e converso.	Likewise, for the impossibility of a temporal proposition there is not required the impossibility of some part, but rather it suffices that the parts are incompossible. Thus, this is impossible: 'God creates while he does not create', because the parts are incompossible. But if is a temporal proposition that denotes that the propositions are true for a different time, then, for it to be impossible, it suffices that the parts be convertible, so that one cannot be true without the other being true, and conversely.
Ex praedictis patet quid requiritur ad hoc quod temporalis sit possibilis vel contingens. Ex praedictis etiam patet quod a temporali ad alteram partem est bona consequentia sed non e converso. Similiter ex temporali sequitur copulativa et non e converso: non enim sequitur 'Adam fuit et Noe fuit, igitur Adam fuit, quando Noe fuit'; nec sequitur 'Iacob fuit et Esau fuit, igitur Iacob fuit, quando Esau fuit'.	From these points it is clear what is required for a temporal proposition to be possible or contingent. From these points it is also clear that there is a good consequence from a temporal proposition to one or other of its parts, but not conversely. Likewise, a copulative proposition follows from a temporal proposition, but not conversely. For this does not follow: 'Adam existed and Noah existed; therefore Adam existed when Noah existed'. Nor does this follow: 'Jacob existed and Esau existed; therefore Jacob existed when Esau existed'.