Authors/Ockham/Summa Logicae/Book III-1/Chapter 48

Latin	English
Cap. 48. De mixtione necessarii et contingentis in secunda figura	Chapter 48. On the mixture of necessary and contingent propositions in the second figure.
In secunda figura si utraque praemissa sumatur in sensu compositionis, non valet mixtio. Unde non sequitur 'nullum hominem esse asinum est necessarium; omne animal irrationale esse asinum est contingens; igitur nullum animal irrationale esse hominem est contingens'. Similiter non sequitur 'omnem personam divinam esse in actu est necessarium; nullam humanitatem esse in actu est contingens; igitur nullam humanitatem esse personam divinam est contingens'.	In the second figure if both premises are taken in the sense of composition, the mixture is not valid. Hence it does not follow that 'it is necessary for no man to be a donkey; it is contingent for every irrational animal to be a donkey; therefore it is contingent for no irrational animal to be a man'. Similarly it does not follow that 'it is necessary for every divine person to be actual; it is contingent for no human to be actual; therefore it is contingent for no human to be a divine person'.
Secundo videndum est quando illa de necessario sumitur in sensu compositionis et illa de contingenti in sensu divisionis. Et est sciendum quod similiter talis mixtio non valet, sive illa de necessario fuerit affirmativa sive negativa.	Secondly, we must see when the proposition of necessity is taken in the sense of composition and the proposition of contingency in the sense of division. And it should be known that similarly such a mixture is not valid, whether the proposition of necessity is affirmative or negative.
Tertio videndum est quando illa de contingenti sumitur in sensu compositionis et illa de necessario in sensu divisionis. Et est sciendum quod similiter talis mixtio non valet.	Thirdly, we must see when the proposition of contingency in the sense of composition and the proposition of necessity in the sense of division. And it must be known that similarly such a mixture is not valid.
Quarto videndum est quando utraque sumitur in sensu divisionis. Et est sciendum primo quod si negativa fuerit de necessario, non sequitur conclusio de contingenti ad utrumlibet, sed sequitur conclusio negativa de possibili et de inesse. Sicut iste syllogismus non valet ‘omnis chimaera de necessitate non est in actu; contingit omnem hominem esse in actu; igitur contingit omnem hominem non esse chimaeram'; sed sequitur ista 'igitur omnis homo potest non esse chimaera' et similiter ista 'nullus homo est chimaera'. Si autem affirmativa fuerit de necessario, sequitur conclusio de inesse et de possibili, non de contingenti.	Fourthly, we must see when both are taken in the sense of division. And it must be known first that if it is negative of necessity, the conclusion does not follow from the contingent to the other, but a negative conclusion follows of possibility and of inherence. Just as this syllogism is not valid, ‘it is necessary that every chimera is not actual; it is possible for every man to be actual; therefore, it is possible for every man not to be a chimera’; but this follows ‘Therefore it is possible that every man is not a chimera’ and similarly this ‘No man is a chimera’. But if it is affirmative of necessity, the conclusion follows of inherence and of possibility, not of contingency.