Authors/Ockham/Summa Logicae/Book III-1/Chapter 26

Latin	English
[Cap. 26. De uniformi ex propositionibus de contingenti non-necessario in prima figura]	[Chapter 26.  On the uniform syllogism made from de contingenti (non-necessary) propositions in the first figure]
Circa uniformem generationem syllogismorum de contingenti non-necessario est primo sciendum, quod in nulla figura est talis uniformis conveniens si omnes propositiones sumantur in sensu compositionis vel si omnes sint talibus aequivalentes; et hoc, quia tunc arguetur per istam regulam ‘praemissae sunt contingentes, igitur conclusio est contingens’, quae regula falsa est, quia ex contingentibus potest sequi tam necessarium quam impossibile. Sequitur enim ‘nullum album est asinus; omnis homo est albus; igitur nullus homo est asinus’, ubi praemissae sunt contingentes et conclusio necessaria. Similiter etiam sequitur ‘omne animal est homo; omnis asinus est animal; igitur omnis asinus est homo’, ubi praemissae sunt contingentes et conclusio impossibilis.	Concerning the uniform generation of de contingenti (non-necessary) syllogisms it should first be known that in no figure is such a uniform syllogism appropriate if all the propositions are taken in the sense of composition, or if they are all  equivalent to such propositions. And this is because then we are arguing from the rule "the premisses are contingent, therefore the conclusion is contingent", which is false, for from contingents there can follow the necessary as well as the impossible.  For "no white thing is a donkey, every man is white, therefore no man is a donkey" follows, where the premisses are contingent and the conclusion is necessary. Similarly "every man is an animal, every donkey is an animal, therefore every donkey is a man" also follows, where the premisses are contingent and the conclusion impossible.
Sciendum est tamen quod numquam possunt praemissae esse contingentes et conclusio impossibilis nisi praemissae repugnent, sicut patet in praedicto exemplo. Sic igitur patet quod uniformis de contingenti ƿ in nulla figura tenet si omnes propositiones sumantur in sensu compositionis.	Yet it should be known that the premisses can never be contingent and the conclusion impossible unless the premisses are conflicting, as is clear in the previous example.  Thus it is clear that a uniform de contingenti does not hold in any figure if all the propositions are taken in the sense of composition.
Et ideo dicendum est de aliis. Et primo de prima figura. Ubi primo sciendum quod sicut illa de possibili habet duplicem acceptionem, ita illa de contingenti. Potest enim subiectum accipi pro eo quod est vel pro eo quod contingit, sicut in ista ‘contingit album esse hominem’. Si enim nullus homo sit albus, tunc haec est falsa ‘contingit album esse hominem’, sumpto subiecto pro eo quod est. Haec enim est falsa ‘aliquid, quod est album, contingit esse hominem’, quia quaelibet singularis est falsa. Si autem subiectum sumatur pro his quae contingunt, vera est. Haec enim est vera ‘quod contingit esse album, contingit esse hominem; Sortem contingit esse album; igitur Sortem contingit esse hominem’.	And therefore this should be discussed in other cases.  And first, concerning the first figure.  Where it should first be known that just as the de possibili has a twofold sense, so does the de contingenti.  For the subject can be taken for what exists, or what exists contingently, for example, "it is contingent that a white thing is a man".  For if no man is white, then "it is contingent that a white thing is a man" is false, taking the subject for what exists. For "something which is white is contingently a man" is false, for every singular is false.  But if the subject is taken for things which exist contingently, it is true.  For "what is contingently white is contingently a man, Socrates is contingently white, therefore Socrates is contingently a man" is true.
Posita ista distinctione sciendum est quod si subiectum maioris sumatur pro his quae contingunt, uniformis est bonus respectu conclusionis de contingenti, subiecto sumpto eodem modo sicut sumitur in minore, quia est syllogismus regulatus per dici de omni vel de nullo. Unde bene sequitur ‘omne quod contingit esse hominem, contingit esse album; omne quod contingit esse nigrum, contingit esse hominem; igitur omne quod contingit esse nigrum contingit esse album’. Nec iste syllogismus indiget aliqua probatione, sed est de se evidens.	Given this distinction, it should be known that if the subject of the major is taken for things which exist contingently, the uniform is good in respect of a de contingenti conclusion, with the subject taken in the same way as it is taken in the minor, for it is a syllogism governed by dici de omni. Hence "everything that is contingently a man is contingently white, everything that is contingently black is contingently a man, therefore everything that is contingently black is contingently white" follows well. Nor does such a syllogism require any proof, but is evident of itself.
Similiter etiam patet quod syllogismus valet si subiectum tam in minore quam in conclusione sumatur pro his quae sunt. Et eodem modo patet quod valet syllogismus quando maior est universalis negativa de contingenti. Sed si subiectum minoris supponat pro his quae sunt et subiectum conclusionis pro his quae contingunt, uniformis non valet, Non enim sequitur ‘omnem hominem contingit esse album; omnem substantiam creatam intellectualem contingit esse hominem; igitur omnem substantiam creatam intellectualem contingit esse albam’, quia posito quod homo sit intelligens et quod nullus angelus sit, conclusio est falsa et praemissae verae.	Similarly, it is also clear that the syllogism is valid if the subject in the minor as well as the conclusion is taken for things which exist.  And in the same way it is clear that the syllogism is valid when the major is a universal negative de contingenti. But if the subject of the minor supposits for things which exist, and the subject of the conclusion supposits for things which exist contingently, the uniform syllogism is not valid.  For "every man is contingently white, every created intellectual substance is contingently a man, therefore every created intellectual substance is contingently white" does not follow, for, given that a man is intelligent and that no angel exists, the conclusion is false and the premisses true.
Et est advertendum quod quando uniformis talis de contingenti ƿ tenet et omnes propositions sumuntur in sensu divisionis, contingit arguere ex omnibus negativis et ex una negativa et alia affirmativa, sive minor fuerit negativa sive affirmativa. Et ratio est, quia tales propositiones convertuntur per oppositas qualitates, et ideo quidquid sequitur ad affirmativam, sequitur ad negativam et e converso. Et ideo hic est bonus syllogismus ‘contingit nullum hominem esse album, contingit nullum nigrum esse hominem; igitur contingit nullum nigrum esse album’.
Si autem maior sumatur in sensu compositionis et minor in sensu divisionis, syllogismus non valet. Nam non sequitur ‘omnem hominem esse Deum est contingens; quamlibet personam divinam contingit esse hominem; igitur quamlibet personam divinam contingit esse Deum’, nam praemissae sunt verae et conclusio falsa. Si enim nullus homo esset nisi Christus, haec esset vera ‘omnis homo est Deus’, et tamen modo est falsa, et per consequens est contingens.
Similiter si maior accipiatur in sensu divisionis et minor in sensu compositionis, consequentia non valet. Non enim sequitur ‘omnem humanitatem contingit assumi a persona divina; haec est contingens: omnis homo est humanitas; igitur contingit omnem hominem assumi a persona divina’, nam praemissae sunt verae et conclusio falsa. Quod enim maior sit vera, patet, quia omne quod potest esse vel est humanitas, potest assumi a persona divina. Quod etiam minor sit vera, patet, quia haec est modo falsa ‘omnis homo est humanitas’ et potest esse vera, quia fuit vera ante incarnationem Verbi, secundum opinionem Aristotelis, sicut alias est ostensum,et eadem ratione posset adhuc esse vera; igitur est contingens. Quod autem conclusio sit falsa, patet, quia si in ista ‘contingit omnem hominem assumi a persona divina’, li homo supponit pro his quae sunt, sic habet aliquam singularem falsam, istam scilicet ‘istum hominem’ - demonstrando Verbum – ‘contingit assumi’; iste enim homo, cum sit Filius Dei, non potest assumi nec assumitur a Verbo, sed ab ipso assumpta est humanitas sua. ƿ