Authors/Ockham/Summa Logicae/Book III-1/Chapter 68

Latin	English
Cap. 68, De syllogismis hypotheticis	Chapter 68. On hypothetical syllogisms.
Dicto de syllogismis categoricis, dicendum est de syllogismis hypotheticis, et primo de syllogismis ex conditionali. Et est sciendum quod semper ex conditionali et antecedente, vel aliquo antecedente ad antecedens illius conditionalis, sequitur consequens. Sicut sequitur 'si homo currit, animal currit; homo currit; igitur animal currit’. Similiter sequitur ‘si homo currit, animal currit; omnis substantia currit; igitur animal currit’. Sed ex conditionali et consequente non sequitur antecedens. Non enim sequitur 'si homo currit, animal currit; animal currit; igitur homo currit'. Similiter ex conditionali maiore et conditionali ƿ minore, habente pro consequente antecedens primae, est bonus syllogismus. Sicut sequitur ‘si homo currit, animal currit; si Sortes currit homo currit; igitur si Sortes currit, animal currit’.	Having said that about categorical syllogisms, we must speak about hypothetical syllogisms, and first about syllogisms from the conditional. And it should be known that a consequent always follows from a conditional and its antecedent, or some antecedent to the antecedent of that conditional. As follows 'if a man runs, an animal runs; man runs; therefore an animal runs'. Similarly, it follows 'if a man runs, an animal runs; every substance runs; therefore an animal runs'. But an antecedent does not follow from a conditional and a consequent. For it does not follow 'if a man runs, an animal runs; an animal runs; therefore a man runs'. Similarly, from a major conditional and a minor conditional, having as its consequent the antecedent of the first, there is a good syllogism. As follows 'if a man runs, an animal runs; if Socrates runs, a man runs; therefore if Socrates runs, an animal runs'.
De aliis dictum est prius in tractatu de propositionibus. Quia ex illis potest elici modus arguendi ex aliis propositionibus hypotheticis, ideo propter brevitatem pertranseo.	The others have been discussed previously in the treatise on propositions. Because from them a method of arguing from other hypothetical propositions can be elicited, I therefore pass over them for the sake of brevity.