Authors/Thomas Aquinas/metaphysics/liber3/lect5

Lecture 5

Latin	English
lib. 3 l. 5 n. 1 Postquam disputavit de prima quaestione quae erat de consideratione causarum, hic intendit disputare de consideratione principiorum demonstrationis, ad quam scientiam pertineat; et circa hoc tria facit. Primo movet quaestionem. Secundo disputat ad unam partem, ibi, unius igitur esse et cetera. Tertio disputat ad aliam partem, ibi, at vero si alia et cetera. Dicit ergo primo, quod dubitatio est de principiis demonstrationis, utrum considerare de his pertineat ad unam scientiam vel ad plures. Et exponit quae sunt demonstrationis principia. Et dicit, quod sunt communes conceptiones omnium ex quibus procedunt omnes demonstrationes, inquantum scilicet singula principia propriarum conclusionum demonstratarum habent firmitatem virtute principiorum communium. Et exemplificat de primis principiis maxime sicut quod necesse est de unoquoque aut affirmare aut negare. Et aliud principium est quod impossibile est idem simul esse et non esse. Est ergo haec quaestio, utrum haec principia et similia pertineant ad unam scientiam vel ad plures. Et si ad unam, utrum pertineant ad scientiam quae est considerans substantiam, vel ad aliam. Et si ad aliam, quam earum oportet nominare sapientiam vel philosophiam primam quam nunc quaerimus.	387. Having debated the first question which had to do with the study of causes, Aristotle’s intention here is to argue dialectically about the science which is concerned with the study of the first principles of demonstration; and in regard to this he does three things. First, he raises the question. Second (388), he argues one side of the question. Third (391), he argues on the other side of the question. Accordingly, he states, first, the problem relating to the first principles of demonstration, namely, whether the study of these principles belongs to one science or to many. Further, he explains what the principles of demonstration are, saying that they are the common conceptions of all men on which all demonstrations are based, i.e., inasmuch as the particular principles of the proper demonstrated conclusions derive their stability from these common principles. And he gives an example of first principles, especially this one, that everything must either be affirmed or denied [of some subject]. Another principle which he mentions is that it is impossible for the same thing both to be and not to be at the same time. Hence the question arises whether these principles and similar ones pertain to one science or to many. And if they pertain to one science, whether they pertain to the science which investigates substance or to another science. And if to another science, then which of these must be called wisdom, or first philosophy, which we now seek.
lib. 3 l. 5 n. 2 Deinde cum dicit unius igitur obiicit ad unam partem quaestionis, scilicet ad ostendendum quod non est unius scientiae considerare principia omnia, supple demonstrationis, et substantiam. Et ponit duas rationes: quarum prima talis est. Cum omnes scientiae utantur praedictis principiis demonstrationis; nulla ratio esse videtur quare magis pertineat ad unam quam ad aliam: nec etiam videtur rationabile, quod eorum consideratio pertineat ad omnes scientias, quia sic sequeretur quod idem tractaretur in diversis scientiis, quod esset superfluum. Videtur igitur relinqui, quod nulla scientia consideret de principiis istis: ergo per quam rationem non pertinet ad aliquam aliarum scientiarum tradere cognitionem de huiusmodi demonstrationis principiis, per eamdem rationem non pertinet ad scientiam cuius est considerare de substantia.	388. Now it would be (199). Here he argues one side of the question with a view to showing that it is not the office of one science to consider all first principles, i.e. the first principles of demonstration and substance. He gives two arguments, of which the first runs thus: since all sciences employ these principles of demonstration, there seems to be no reason why the study of them should pertain to one science rather than to another; nor again does it seem reasonable that they should be studied by all sciences, because then it would follow that the same thing would be treated in different sciences; but that would be superfluous. Hence it seems to follow that no science considers these principles. Therefore, for the very same reason that it does not belong to any of the other sciences to give us a knowledge of such principles, for this reason too it follows that it does not belong to the science whose function it is to consider substance.
lib. 3 l. 5 n. 3 Secunda ratio ponitur ibi simul autem, quae talis est. Modus de quo est cognitio in scientiis est duplex. Unus modus secundum quod de unoquoque cognoscitur quid est. Alius modus secundum quod cognitio per demonstrationem acquiritur. Primo autem modo non pertinet ad aliquam scientiam tradere cognitionem de principiis demonstrationis, quia talis cognitio principiorum praesupponitur ante omnes scientias. Quod enim unumquodque horum sit ens ex nunc novimus, idest statim a principio cognoscimus quid significent haec principia, per quorum cognitionem statim ipsa principia cognoscuntur. Et, quia talis cognitio principiorum inest nobis statim a natura, concludit, quod omnes artes et scientiae, quae sunt de quibusdam aliis cognitionibus, utuntur praedictis principiis tamquam naturaliter notis.	389. But at the same time (200). Here he gives the second argument, which runs thus. In the sciences there are two methods by which knowledge is acquired. One is that by which the whatness of each thing is known, and the other is that by which knowledge is acquired through demonstration. But it does not belong to any science to give us a knowledge of the principles of demonstration by means of the first method, because such knowledge of principles is assumed to be prior to all the sciences. For "we already know" what each one of them is, i.e., we know from the very beginning what these principles signify, and by knowing this the principles themselves are immediately known. And since such knowledge of principles belongs to us immediately, he concludes that all the arts and sciences which are concerned with other kinds of cognitions make use of these pinciples as things naturally known by us.
lib. 3 l. 5 n. 4 Similiter autem probatur, quod praedictorum principiorum cognitio non traditur in aliqua scientia per demonstrationem; quia si esset aliqua demonstratio de eis, oporteret tria tunc principia considerari; scilicet genus subiectum, passiones, et dignitates. Et ad huius manifestationem, subdit, quod impossibile est de omnibus esse demonstrationem: non enim demonstrantur subiecta, sed de subiectis passiones. De subiectis vero oportet praecognoscere an est et quid est, ut dicitur in primo posteriorum. Et hoc ideo, quia necesse est demonstrationem esse ex aliquibus, sicut ex principiis, quae sunt dignitates, et circa aliquod, quod est subiectum, et aliquorum, quae sunt passiones. Ex hoc autem statim manifestum est ex uno horum trium, quod dignitates non demonstrantur; quia oporteret quod haberent aliquas dignitates priores, quod est impossibile. Unde praetermisso hoc modo procedendi tamquam manifesto, procedit ex parte subiecti. Cum enim una scientia sit unius generis subiecti, oporteret quod illa scientia, quae demonstraret dignitates, haberet unum subiectum. Et sic oporteret, quod omnium scientiarum demonstrativarum esset unum genus subiectum, quia omnes scientiae demonstrativae utuntur huiusmodi dignitatibus.	390. But it is proved in the same way that a knowledge of these principles is not presented to us in any science by means of demonstration, because if there were demonstration of them, then three principles would have to be considered, namely, some subjectgenus, its properties and the axioms. In order to clarify this he adds that there cannot be demonstration of all things; for subjects are not demonstrated but properties are demonstrated of subjects. Concerning subjects, however, it is necessary to know beforehand whether they exist and what they are, as is stated in Book I of the Posterior Analytics. The reason is that demonstration must proceed from certain things as principles, which are the axioms, and be about something, which is the subject, and [be demonstration] of certain things, which are properties. Now according to this it is immediately evident of one of these three, i.e., the axioms, that they are not demonstrated, otherwise there would have to be certain axioms prior to the axioms; but this is impossible. Therefore, having dismissed this method of procedure as obvious, he proceeds to consider the subject-genus. For since one science has one subject-genus, then that science which would demonstrate axioms would have one subject-genus. Thus there would have to be one subjectgenus for all demonstrative sciences, because all demonstrative sciences use axioms of this kind.
lib. 3 l. 5 n. 5 Deinde cum dicit at vero obiicit ad aliam partem. Si enim dicatur, quod alia scientia sit, quae est de huiusmodi principiis, et alia, quae est de substantia, remanebit dubitatio quae ipsarum sit principalior et prior. Ex una enim parte dignitates sunt maxime universales, et principia omnium, quae traduntur in quibuscumque scientiis. Et secundum hoc videtur quod scientia, quae est de huiusmodi principiis, sit principalissima. Ex alia vero parte, cum substantia sit primum et principale ens; manifestum est, quod prima philosophia est scientia substantiae. Et si non est eadem scientia substantiae et dignitatum non erit de facili dicere cuius alterius sit considerare veritatem et falsitatem circa dignitates, si non est primi philosophi qui considerat substantiam.	391. But on the other hand (201). Here he argues the other side of the question. For if it is said that there is one science which deals with sucn principles, and another which deals with substance, the problem will remain as to which of these sciences is the more important and prior one. For, on the one hand, since the axioms are most universal and are the principles of everything that is treated in any of the sciences, it seems that the science which deals with such principles is the most important one. Yet, on the other hand, since substance is the first and principal kind of being, it is evident that first-philosophy is the science of substance. And if it is not the same science which deals with substance and with the axioms, it will not be easy to state to which of the other sciences it belongs to consider the truth and falsity of these axioms, i.e., if it does not belong to first philosophy, which considers substance.
lib. 3 l. 5 n. 6 Hanc autem quaestionem determinat philosophus in quarto huius; et dicit, quod ad philosophum potius pertinet consideratio dignitatum, inquantum ad ipsum pertinet consideratio entis in communi, ad quod per se pertinent huiusmodi principia prima, ut maxime apparet in eo quod est maxime primum principium, scilicet quod impossibile est idem esse et non esse. Unde omnes scientiae particulares utuntur huiusmodi principiis sicut utuntur ipso ente, quod tamen principaliter considerat philosophus primus. Et per hoc solvitur ratio prima. Secunda autem ratio solvitur per hoc, quod philosophus non considerat huiusmodi principia tamquam faciens ea scire definiendo vel absolute demonstrando; sed solum elenchice, idest contradicendo disputative negantibus ea, ut in quarto dicetur.	392. The Philosopher answers this question in Book IV (590) of this work. He says that the study of the axioms belongs chiefly to the [first] philosopher inasmuch as it pertains to him to consider being in general, to which first principles of this kind essentially belong, as is most evident in the case of the very first principle: it is impossible for the same thing both to be and not to be [at the same time]. Hence all the particular sciences use principles of this kind just as they use being itself, although it is the first philosopher who is chiefly concerned with this. And the first argument is solved in this way. But the second argument is solved thus: the [first] philosopher does not consider principles of this kind in such a way as to make them known by defining them or by demonstrating them in an absolute sense, but by refutation, i.e., by arguing disputatively against those who deny them, as is stated in Book IV (608).