Authors/Ockham/Summa Logicae/Book III-2/Chapter 30

Latin	English
CAP. 30. QUALITER PROPOSITIO IN QUA PRAEDICATUR DIFFERENTIA DE SPECIE ABSOLUTA DEMONSTRARI POTEST.	Chapter 30. How a proposition where a difference is predicated of the absolute species can be demonstrated
Quamvis propositio in qua praedicatur genus absolutum de specie mere absoluta composita ex conceptibus simplicibus demonstrari non possit nec a priori nec a posteriori, tamen propositio in qua praedicatur differentia de specie tali a posteriori demonstrari potest.	Although a proposition in which an absolute genus is predicated of a merely absolute species composed of simple concepts cannot be demonstrated either a priori or a posteriori, yet a proposition in which a difference is predicated of such a species can be demonstrated a posteriori.
Nam differentia, sicut dictum est prius, importat unam partem in obliquo et ideo quia per effectus demonstrari potest talem rem habere talem partem, ideo per effectus demonstrari potest differentia talis de specie tali.	For difference, as was said before, implies one part obliquely, and therefore because it can be shown by effects that such a thing has such a part, therefore it can be shown by effects that such a difference from such a species can be shown.
Verbi gratia si aliquis habeat notitiam propriam animae sensitivae et per conƿsequens sciat quid significat hoc vocabulum ‘sensitivum’ et videat aliquod corpus cuius habeat notitiam simplicem et propriam talibus corporibus, et tamen ignoret an habeat animam sensitivam, iste per aliquos effectus competentes cuilibet tali corpori potest demonstrative probare quod omne tale corpus habet animam sensitivam et per consequens quod est sensitivum.	For example, if someone has the proper knowledge of a sensitive soul and by consequence knows what this term 'sensitive' means and sees a body of which he has a simple and proper knowledge of such bodies, and yet does not know whether it has a sensitive soul, he can demonstratively prove by certain effects competent to any such body that every such body has a sensitive soul and consequently that it is sensitive.
Et per talem modum probavit Aristoteles per transmutationem et motum quod in istis generabilibus et corruptibilibus est materia distincta a forma et per consequens quod sunt materialia, cum tamen ‘materiale’ sit differentia essentialis eorum.	And in such a way Aristotle proved, by transmutation and motion, that in these generable and corruptible things there is matter distinct from form, and consequently that they are material, since 'material' is their essential difference.
Per talem etiam modum potest demonstrative probari quod in homine sunt plures formae, si in eo sint plures formae; quamvis forte hoc non sit facile multis, immo forte quamvis de multis nulli sit hoc possibile pro statu isto.	By such a method it can also be demonstratively proved that there are many forms in man, if there are many forms in him; although perhaps this is not easy for many, and perhaps for many this is not possible for any of them in this state.
Oportet tamen scire quod propositio in qua praedicatur differentia de notitia distincta et perfecta, quando scilicet nihil cogniti latet cognoscentem, nullo modo est demonstrabilis, quia forte talis notitia est notitia definitiva.	However, it is necessary to know that the proposition in which a difference is predicated of distinct and complete information, namely when nothing known is hidden from the knower, is in no way demonstrable, because perhaps such information is definitive information.
Sed quidquid sit de hoc, dico quod de talibus conceptibus specificis substantiarum, quales nos de facto habemus, potest differentia demonstrari a posteriori, licet non a priori. Quod saltem verum est quod differentia non potest demonstrari a priori de specie cui primo competit, sive possit demonstrari per medium sumptum a causa extrinseca de aliquo contento sub specie prima sive non.	But whatever may be said about this, I say that with regard to such specific conceptions of substances as we actually have, a difference can be shown from the latter, though not from the former. What is at least true is that the difference cannot be demonstrated a priori from the species to which it first belongs, whether it can be demonstrated by means of an extrinsic cause from some content under the first species or not.
Et illud quod dictum est de differentia quae praedicatur in recto de specie intelligendum est de illis quae praedicantur in obliquo de specie et significant partes essentiales rei. Unde sicut a posteriori demonstrari potest quod animal est materiale, ita a posteriori demonstrari potest quod animal componitur ex materia.	And what has been said about the difference which is predicated directly of the species is to be understood of those that are predicated obliquely of the species and signify the essential parts of the thing. Hence, just as it can be demonstrated a posteriori that an animal is material, so it can be demonstrated a posteriori that an animal is composed of matter.
Et ita de aliis, proportionaliter, est dicendum.	And so it must be said of others, proportionally.