Authors/Ockham/Summa Logicae/Book III-1/Chapter 64

 

Latin	English
[Cap. 64. De mixtione propositionum modalium aliarum a praedictis quatuor]	[Chapter 64. On the mixture of modal propositions other than the previous four]
Si fiat mixtio ex propositionibus modalibus aliorum modorum ab illis quatuor, aut utraque propositio sumitur in sensu compositionis sive in tali sensu per quem denotatur modus verificari de sua de inesse, aut sub alio sensu. Si primo modo, raro valet mixtio, quia numquam valet nisi quando tales modi non possunt verificari de praemissis nisi aliquis eorum verificetur de conclusione sequente ex praemissis. Quod non semper tenet, quia quamvis una praemissa sit scita et alia credita, non oportet conclusionem sciri. Et ita est de aliis.	If a mixture of modal propositions in other modes than the previous four is made, either both propositions are taken in the sense of composition, or in such a sense through which the mode is denoted to be verified of its assertoric proposition, or in another sense.  If in the first mode, the mixture will rarely be valid, for it is never valid unless such modes cannot be verified of the premisses unless one of them is verified of the conclusion following from the premisses.  This does not always hold, for although one proposition is known and another believed, the conclusion does not have to be known.  And so for the others.
Si autem praemissae sumantur in alio sensu, tunc si minor inferat suam de inesse in prima figura, semper conclusio sequitur in eadem figura de eodem modo de quo est maior. Sicut sequitur 'omnis homo per se est animal; aliquod album scitur esse homo; igitur aliquod album per se est animal', quia ex eadem maiore et illa de inesse sequitur eadem conclusio; et per consequens eadem conclusio sequitur ex maiore et antecedente ad illam de inesse.	But if the premisses are taken in another sense, then if the minor implies its assertoric in the first figure, the conclusion always follows in the same figure of the same mode of which it is the major.  For example, 'every man per se is an animal, something white is known to be a man, therefore something white per se is an animal', for from the same major and the assertoric, the same conclusion follows, and as a consequence the same conclusion follows from the major and the antecedent to that assertoric.
Per ista et praedicta potest studiosus cognoscere quando mixtio ex talibus valet vel non valet in alias figuris. ƿ	Though this, and from what was previously said, the keen student can know when a mixture from such propositions is valid or not valid in other figures.
Et ista de mixtionibus ad praesens sufficient, quamvis multa causa brevitatis sint omissa, quae tamen ex praedictis a studiosis elici possunt.	And suffices, at present, about mixed syllogisms, although many things have been left out by reason of brevity, which can still be found out by the studious from what has been said.
Illa autem quae dicit Aristoteles in mixtionibus suis, quae aliquibus de praedictis videntur contradicere, solvi possunt per aliquas regulas superius datas, quorum solutio expressius patebit super librum Priorum, si contingat me illum librum exponere.