Authors/Ockham/Summa Logicae/Book III-1/Chapter 13

Latin	English
Cap. 13. quomodo aliquando ex omnibus affirmativis in secunda figura est bonum argumentum	Chapter 13. On how sometimes there is a good argument from affirmative propositions in the second figure.
Quamvis dictum sit superius quod ex affirmativis non contingit arguere in secunda figura, tamen ab illa regula generali sunt duo casus excipiendi. Primus est, si medius terminus sit terminus discretus: tunc enim ex duabus affirmativis contingit inferre conclusionem affirmativam; sicut bene sequitur ‘omnis homo est Sortes; Plato est Sortes; igitur Plato est homo’. Et potest talis syllogismus probari, quia conversis propositionibus erit syllogismus expositorius in tertia figura.	Although it was said above that it is not possible to argue from affirmatives in the second figure, nevertheless there are two cases of exception from that general rule. The first is if the middle term is a discrete term: for then it is possible to infer an affirmative conclusion from two affirmatives; as it follows well ‘every man is Socrates; Plato is Socrates; therefore Plato is man’. And such a syllogism can be proved, because with the propositions reversed it will be an expository syllogism in the third figure.
Secundus casus est quando terminus medius sumitur cum signo universali: tunc enim semper contingit inferre conclusionem affirmativam in qua maior extremitas praedicatur de minore<refAmanuensis codicis D hic notat in margine: ‘Haec probatio non concludit necessario’.</ref>. Bene enim sequitur ‘omnis homo est omne risibile; Sortes est omne risibile; igitur Sortes est homo’. Iste autem discursus probatur per hoc quod semper talis propositio maior convertitur in unam universalem affirmativam, qua conversione facta patet quod discursus est in prima figura, regulatus per dici de omni. Bene enim sequitur ‘aliquis homo est omne animal, igitur omne animal est homo’. Et ita talis discursus est bonus in secunda figura ‘omne musicum est omnis homo; Sortes est omnis homo vel Sortes est homo; igitur Sortes est musicus’. Nam conversa ista maiore ‘omne musicum est omnis homo’ in istam ‘omnis homo est musicus’ sylloƿgismus regulabitur per dici de omni in prima figura, sic arguendo ‘omnis homo est musicus; Sortes est homo; igitur Sortes est musicus'.	The second case is when the middle term is taken with a universal sign: for then it is always possible to infer an affirmative conclusion in which the major extreme is predicated of the minor <ref The scribe of codex D here notes in the margin: ‘This proof does not necessarily follow’.</ref>. For it follows well ‘every man is all that is able to laugh; Socrates is all that is able to laugh; therefore Socrates is a man’. But this discourse is proven by the fact that such a major proposition is always converted into one universal affirmative, by which conversion it is clear that the discourse is in the first figure, regulated by the dici de omni (to be said of all). For it follows well ‘every animal is some man, therefore every animal is a man’. And thus such a discourse is good in the second figure ‘every musician is some man; Socrates is some man or Socrates is a man; therefore Socrates is a musician’. For, having converted the major ‘every musician is every man’ into the syllogism ‘every man is a musician’, the syllogism will be regulated by dici de omni (to be said of all) in the first figure, thus arguing ‘every man is a musician; Socrates is a man; therefore Socrates is a musician’.
Et est sciendum quod in duobus praedictis casibus non solum contingit arguere ex affirmativis universalibus, sed etiam contingit arguere ex omnibus affirmativis particularibus. Et eodem modo probantur syllogismi tales ex particularibus sicut ex universalibus.	And it should be known that in the two aforementioned cases it is not only possible to argue from universal affirmatives, but it is also possible to argue from all particular affirmatives. And in the same way such syllogisms are proven from particulars as from universals.
Et ideo tales regulae generales ‘ex particularibus nihil sequitur’, ‘oportet alteram praemissarum in secunda figura esse negativam’ intelligendae sunt; quod non semper contingit arguere ex particularibus nec semper ex affirmativis. Tamen in praedictis casibus contingit arguere tam ex particularibus quam ex affirmativis. Et tenet talis discursus non gratia materiae sed gratia formae, quia in omni materia, observato quod medius terminus sit terminus discretus vel sumptus cum signo universali in maiori, discursus erit bonus.	And therefore, such general rules as ‘nothing follows from the particulars’, ‘the other of the premises in the second figure must be negative’ are to be understood; that it is not always possible to argue from particulars nor always from the affirmatives. However, in the aforementioned cases it is possible to argue both from the particulars and from the affirmatives. And such a discourse holds not by virtue of the matter but by virtue of the form, because in every matter, observing that the middle term is a discrete term or taken with a universal sign in the major, the discourse will be good.