Authors/Ockham/Summa Logicae/Book III-2/Chapter 19

Latin	English
CAP. 19. QUOMODO DEMONSTRATIO PROPTER QUID ET DEMONSTRATIO QUIA DIFFERUNT IN GENERALI?.	Chapter 19. How do demonstration propter quid (because of what) and demonstration quia (because) differ in general?
Ostenso quod aliqua est demonstratio quia et alia propter quid, videndum est quomodo istae demonstrationes differunt in generali, et quomodo differunt scientia propter quid et scientia quia.	I show that there is some demonstration because and others because of what; we must see how these demonstrations differ in general, and how the knowledge because of what and the knowledge because differ.
Pro quo sciendum est quod illa vocatur demonstratio propter quid quae est ex propositionibus necessariis prioribus, qua habita cessat omnis dubitatio et omnis quaestio circa conclusionem.	For which reason it must be known that it is called a demonstration because of what it is from the previous necessary propositions, and when it is held, all doubt and all question about the conclusion ceases.
Sicut si sciatur quod luna eclipsatur per hoc quod scitur quod terra interponitur inter solem et lunam cessat omnis quaestio de ista conclusione ‘luna eclipsatur’: nec enim quaeritur utrum luna eclipsetur nec quare luna eclipsatur.	Just as if it is known that the moon is eclipsed by the fact that it is known that the earth is interposed between the sun and the moon, all question about the conclusion 'the moon is eclipsed' ceases: for it is not asked whether the moon is eclipsed or why the moon is eclipsed.
Forte tamen non oportet quod cesset quaestio circa quamlibet praemissarum.	Perhaps, however, it is not necessary that the question ceases about any of the premises.
Demonstratio autem quia est illa demonstratio quae non est ex prioribus vel qua habita non cessat omnis quaestio circa conclusionem. ƿ Exemplum primi est, si demonstretur quod terra interponitur inter solem et lunam per hoc quod luna eclipsatur: praemissae non sunt priores conclusione sed posteriores.	But the demonstration because is that demonstration which is not from the previous ones, or by which it is held, does not stop all the question about the conclusion. An example of the first is if it is shown that the earth is interposed between the sun and the moon by the fact that the moon is eclipsed: the premises are not the former of the conclusion, but the latter.
Exemplum secundi est, si arguatur sic ‘nullum non-animal respirat; planta est non-animal; igitur planta non respirat’. Iste syllogismus ex prioribus est, adhuc tamen contingit quaerere quare planta non respirat. Et propter hoc iste syllogismus non est demonstratio propter quid sed quia; et hoc quia per talem syllogismum sufficienter scitur quod planta non respirat, sed non sufficienter scitur quare non respirat.	An example of the second is if it is argued that 'no non-animal breathes; a plant is a non-animal; therefore the plant does not breathe. This syllogism is from the former, but it still happens to ask why the plant does not breathe. And for this reason this syllogism is not a demonstration because of what, but because; and this because by such a syllogism it is sufficiently known that the plant does not breathe, but it is not sufficiently known why it does not breathe.