Authors/Ockham/Summa Logicae/Book III-2/Chapter 20

Latin	English
CAP. 20. QUOT MODIS DIFFERT DEMONSTRATIO QUIA A DEMONSTRATIONE PROPTER QUID?.	Chapter 20. In how many ways does a demonstration because differ from a demonstration because of what?
Ista demonstratio quia sive scientia quia, secundum Aristotelem, duobus modis specialiter differt a demonstratione propter quid: uno modo in eadem scientia, alio modo in diversis scientiis.	This demonstration because or science because, according to Aristotle, differs in two ways specifically from demonstration because of what: one way in the same science, another way in different sciences.
Pro quo est primo sciendum quod hoc nomen ‘scientia’ dupliciter ad praesens accipitur.	For which it is first to be known that this word 'science' is taken at present in two ways.
Uno modo significat collectionem multorum habituum, principiorum scilicet et conclusionum, ordinem determinatum habentium. Et sic accipit Philosophus hic scientiam. Aliter accipitur pro aliquo uno habitu et non pro aliqua collectione plurium habituum. Et sic loquitur Philosophus in diversis locis de scientia. Accipiendo igitur scientiam primo modo: uno modo differt demonstratio quia a demonstratione propter quid in eadem scientia sive scientia quia a scientia propter quid.	In one way, it means a collection of many attitudes, that is, principles and conclusions, having a determined order. And so the Philosopher receives knowledge here. It is taken differently for any one habit and not for any collection of many habits. And so the Philosopher speaks in different places about science. Therefore, accepting knowledge in the first way: demonstration because differs from demonstration for the sake of what in the same science, or knowledge because from knowledge for the sake of what.
Et hoc dupliciter, secundum quod tactum est in praecedenti capitulo: uno modo, quia demonstratio quia, licet sit per prius, non tamen per causam immediatam; hoc est, non est per medium convertibile.	And this in two ways, according to what was touched upon in the previous chapter: in the first way, because the demonstration because, although it may be through a prior, is not through an immediate cause; that is, it is not convertible through the medium.
Aliquando autem demonstratio quia est per ƿ posterius, ita quod in praemissis non accipitur aliquid importans causam quare sic est sicut denotatur per conclusionem sed magis e converso.	But sometimes the demonstration because it is by a posterior, so that something is not taken in the premises which carries the cause why it is so, as is denoted by the conclusion, but rather the other way around.
Verbi gratia, causa quare planetae non scintillant, est quia sunt prope.	For example, the reason why planets don't sparkle is because they are close.
Tunc si arguatur sic ‘planetae sunt prope, ergo non scintillant’, est demonstratio propter quid; si arguatur e converso, erit demonstratio quia. Et ita, universaliter, quando propositio prior scitur evidenter per hoc quod praemissae posteriores sciuntur evidenter, est demonstratio quia; immo etiam sufficit quod una praemissarum sit posterior conclusione. Similiter, quando demonstratur effectus non per causam immediatam sed remotam, tunc est demonstratio quia.	Then if it is argued that 'the planets are near, therefore they do not sparkle', it is a demonstration of why; if it is argued on the contrary, it will be a demonstration because And so, universally, when the prior proposition is clearly known by the fact that the posterior premises are clearly known, it is a demonstration because; nay, it is also sufficient that one of the premises is an a posteriori conclusion. Similarly, when an effect is demonstrated not by an immediate cause but by a remote one, then it is a demonstration because.
Sed sciendum est quod talis demonstratio semper est negativa et in secunda figura, ita quod affirmative non contingit sic demonstrare. Et vocatur hic causa remota non aliqua res quae est causa causae vel causa plurium, sed vocatur hic causa negatio alicuius ex qua sequitur negatio alterius et non e converso.	But it must be known that such a demonstration is always negative and in the second form, so that it does not happen to demonstrate in the affirmative. And here what is called a remote cause is not some thing which is the cause of a cause or the cause of many, but what is called a cause here is the negation of something from which the negation of another follows, and not the other way around.
Sicut sequitur ‘hoc non est animal, ergo hoc non respirat’, sed e converso non sequitur. Et tale medium non potest esse medium nisi in secunda figura. Et eodem modo, sicut potest negative syllogizari per talem causam non convertibilem cum effectu, ita potest syllogizari negative in secunda figura per effectum non convertibilem; et utraque erit demonstratio quia, non propter quid. Oportet etiam scire quod sicut in eadem scientia unus demonstrat effectum per causam et habet demonstrationem propter quid et alius e converso demonstrat eandem causam per eundem effectum et habet demonstrationem quia, ita idem potest primo demonstrare idem per effectum et postea per causam, eo quod non est inconveniens quod idem sit effectus unius et causa alterius.	It follows that 'this is not an animal, therefore this does not breathe', but it does not follow the other way around. And such a medium cannot be a medium except in the second figure. And in the same way, as it is possible to syllogize negatively through such a non-reversible cause with an effect, so it is possible to syllogize negatively in the second figure through a non-reversible effect; and both will be demonstrations because, not because of what. It is also necessary to know that just as in the same science one person demonstrates an effect through a cause and has a demonstration because of it, and another, on the contrary, demonstrates the same cause through the same effect and has a demonstration because, so the same person can first demonstrate the same thing through the effect and later through the cause, because it is not inconvenient that the effect of one and the cause of another be the same.
Tamen pro modo loquendi oportet scire quod nullus demonstrat causam per effectum vel e converso, quasi causa extra vel effectus intret demonstrationem, cum demonstratio non componatur nisi ex conceptibus seu intentionibus animae vel ex vocibus vel scriptis, sed ideo diciƿmus demonstrari causam per effectum vel e converso quia quandoque praemissae exprimunt causam quare sic est sicut denotatur per conclusionem, et quandoque e converso.	However, as a way of speaking, we must know that no one demonstrates a cause through an effect or vice versa, as if an external cause or effect enters into the demonstration, since the demonstration is not composed except from the concepts or intentions of the soul or from words or writings, but therefore we say that the cause is demonstrated through the effect or vice versa, because sometimes the premises express the reason why it is as it is denoted by the conclusion, and sometimes vice versa.
Unde pro protervis oportet prompte scire aequivocationem huius nominis ‘causa’, de qua breviter tactum est prius et amplius dicetur inferius.	Therefore, for those who are stubborn, it is necessary to know immediately the equivocation of this word 'cause', which was briefly touched on before and will be discussed further below.