Authors/Thomas Aquinas/posteriorum/L1/Lect2

Lecture 2 Extent and order of the pre-existent knowledge required for obtaining science

Latin	English
	Lecture 2 (71a11-23) EXTENT AND ORDER OF THE PRE-EXISTENT KNOWLEDGE REQUIRED FOR OBTAINING SCIENCE
lib. 1 l. 2 n. 1 Postquam ostendit philosophus quod omnis disciplina ex praeexistenti fit cognitione nunc ostendit quis sit modus praecognitionis. Et circa hoc duo facit: primo, determinat modum praecognitionis quantum ad illa quae oportet praecognoscere ut habeatur cognitio conclusionis, cuius scientia quaeritur; secundo, determinat modum praecognitionis ipsius conclusionis, cuius scientia per demonstrationem quaeritur; ibi: antequam sit inducere et cetera. In praecognitione autem duo includuntur, scilicet cognitio et cognitionis ordo. Primo ergo, determinat modum praecognitionis quantum ad cognitionem ipsam; secundo, quantum ad cognitionis ordinem; ibi: est autem cognoscere et cetera.	After showing that every discipline is developed from knowledge already existing, the Philosopher shows what is the extent of this preexisting knowledge. Concerning this he does two things. First, he determines the extent of pre-existing knowledge in regard to the things that must be known in order to attain knowledge of the conclusion, of which scientific knowledge is sought. Secondly, he determines the extent of pre-existing knowledge of the conclusion, of which scientific knowledge is sought through demonstration (71a24) [L.3]. Now two things are included in pre-existing knowledge, namely, the knowledge and the order of the knowledge. First, therefore, he determines the extent of pre-existing knowledge so far as the knowledge itself is concerned. Secondly, so far as the order of the knowledge is concerned (71a16).
lib. 1 l. 2 n. 2 Circa primum sciendum est quod id cuius scientia per demonstrationem quaeritur est conclusio aliqua in qua propria passio de subiecto aliquo praedicatur: quae quidem conclusio ex aliquibus principiis infertur. Et quia cognitio simplicium praecedit cognitionem compositorum, necesse est quod, antequam habeatur cognitio conclusionis, cognoscatur aliquo modo subiectum et passio. Et similiter oportet quod praecognoscatur principium, ex quo conclusio infertur, cum ex cognitione principii conclusio innotescat.	In regard to the first it should be noted that the object of which scientific knowledge is sought through demonstration is some conclusion in which a proper attribute is predicated of some subject, which conclusion is inferred from the principles. And because the knowledge of simple things precedes the knowledge of compound things, it is necessary -that the subject and the proper attribute be somehow known before knowledge of the conclusion is obtained. In like manner it is required thatthe principle be known from which the conclusion is inferred, for the conclusion is made known from a knowledge of the principle.
lib. 1 l. 2 n. 3 Horum autem trium, scilicet, principii, subiecti et passionis est duplex modus praecognitionis, scilicet, quia est et quid est. Ostensum est autem in VII metaphysicae quod complexa non definiuntur. Hominis enim albi non est aliqua definitio et multo minus enunciationis alicuius. Unde cum principium sit enunciatio quaedam, non potest de ipso praecognosci quid est, sed solum quia verum est. De passione autem potest quidem sciri quid est, quia, ut in eodem libro ostenditur, accidentia quodammodo definitionem habent. Passionis autem esse et cuiuslibet accidentis est inesse subiecto: quod quidem demonstratione concluditur. Non ergo de passione praecognoscitur quia est, sed quid est solum. Subiectum autem et definitionem habet et eius esse a passione non dependet; sed suum esse proprium praeintelligitur ipsi esse passionis in eo. Et ideo de subiecto oportet praecognoscere et quid est et quia est: praesertim cum ex definitione subiecti et passionis sumatur medium demonstrationis.	Now the extent of pre-existent knowledge of these three items, i.e., of the principle, of the subject, and of the proper attribute, is limited to knowing two things about them, namely, that each is and what each is. But, as stated in Metaphysics VII, complex things are not defined. For there is no definition of “white man,” much less of an enunciation [proposition]. Hence since a principle is an enunciation, there cannot be preexisting knowledge of what it is but only of the fact that it is true. But in regard to the proper attribute, it is possible to know what it is, because, as is pointed out in the same book, accidents do have some sort of definition. Now the being of a proper attribute and of any accident is being in a subject; and this fact is concluded by the demonstration. Consequently, it is not known beforehand that the proper attribute exists, but only what it is. The subject, too, has a definition; moreover, its being does not depend on the proper attribute—rather its own being is known before one knows the proper attribute to be in it. Consequently, it is necessary to know both what the subject is and that it is, especially since the medium of demonstration is taken from the definition of the subject of the proper attribute.
lib. 1 l. 2 n. 4 Propter hoc ergo dicit philosophus quod dupliciter necessarium est praecognoscere: quia duo sunt quae praecognoscuntur de his, quorum praecognitionem habemus, scilicet quia est et quid est. Et quod alia sunt de quibus necesse est primo cognoscere quia sunt, sicut principia de quibus postea exemplificat, ponens in exemplo primum omnium principiorum, scilicet quod de unoquoque est affirmatio vel negatio vera.	This, therefore, is why the Philosopher says (71a11) that it is necessary to know beforehand in two ways; because two items are known beforehand concerning things of which we have pre-existing knowledge, namely, that it is and what it is. [Then he goes on to say] that there are some things concerning which it is necessary first to know that they are, such as principles, concerning which he then gives examples, citing as one example the first of all principles, namely, “There is true affirmation or negation about everything.”
lib. 1 l. 2 n. 5 Alia vero sunt, de quibus oportet praeintelligere quid est quod dicitur, idest quid significatur per nomen, scilicet de passionibus. Et non dicit quid est simpliciter, sed quid est quod dicitur, quia antequam sciatur de aliquo an sit, non potest sciri proprie de eo quid est: non entium enim non sunt definitiones. Unde quaestio, an est, praecedit quaestionem, quid est. Sed non potest ostendi de aliquo an sit, nisi prius intelligatur quid significatur per nomen. Propter quod etiam philosophus in IV metaphysicae, in disputatione contra negantes principia docet incipere a significatione nominum. Exemplificat autem de triangulo, de quo oportet praescire quoniam nomen eius hoc significat, quod scilicet in sua definitione continetur.	Again, there are other things, namely, proper attributes, concerning which it is necessary to know what is said to be predicated, i.e., what is signified by their name. And he does not say unqualifiedly, “what it is,” but “what is said to be predicated,” because one cannot properly know of something what it is before it is known that it is. For there are no definitions of non-beings. Hence the question, whether it is, precedes the question, what it is. But “whether a thing is” cannot be shown unless it is known beforehand what is signified by its name. On this account the Philosopher teaches in Metaphysics IV that in disputing against those who deny principles one must begin with the meanings of names. An example of this is “triangle,” concerning which one must know beforehand that its name signifies such and such, namely what is contained in its definition.
Cum enim accidentia quodam ordine ad substantiam referantur, non est inconveniens id quod est accidens in respectu ad aliquid, esse etiam subiectum in respectu alterius. Sicut superficies est accidens substantiae corporalis: quae tamen superficies est primum subiectum coloris. Id autem quod est ita subiectum, quod nullius est accidens, substantia est. Unde in illis scientiis, quarum subiectum est aliqua substantia, id quod est subiectum nullo modo potest esse passio, sicut est in philosophia prima, et in scientia naturali, quae est de subiecto mobili.	But since accidents are referred to their subjects in a definite order, it is not impossible for something which is an accident in relation to one thing to be a subject in relation to something else: for example, a surface is an accident in relation to a bodily substance, but in relation to color it is the first subject. However, that which is a subject in such a way as never to be an accident of anything else is a substance. Hence in those sciences whose subject is a substance, that which is the subject can never be a proper attribute, as in first philosophy and in natural science, which treats of mobile being.
In illis autem scientiis, quae sunt de aliquibus accidentibus, nihil prohibet id, quod accipitur ut subiectum respectu alicuius passionis, accipi etiam ut passionem respectu anterioris subiecti. Hoc tamen non in infinitum procedit. Est enim devenire ad aliquod primum in scientia illa, quod ita accipitur ut subiectum, quod nullo modo ut passio; sicut patet in mathematicis scientiis, quae sunt de quantitate continua vel discreta. Supponuntur enim in his scientiis ea quae sunt prima in genere quantitatis; sicut unitas, et linea, et superficies et alia huiusmodi. Quibus suppositis, per demonstrationem quaeruntur quaedam alia, sicut triangulus aequilaterus, quadratum in geometricis et alia huiusmodi. Quae quidem demonstrationes quasi operativae dicuntur, ut est illud, super rectam lineam datam triangulum aequilaterum constituere. Quo adinvento, rursus de eo aliquae passiones probantur, sicut quod eius anguli sunt aequales aut aliquid huiusmodi. Patet igitur quod triangulus in primo modo demonstrationis se habet ut passio, in secundo se habet ut subiectum. Unde philosophus hic exemplificat de triangulo ut est passio, non ut est subiectum, cum dicit quod de triangulo oportet praescire quoniam hoc significat.	But in those sciences which bear upon accidents, nothing prevents a same thing from being taken as a subject in reference to one proper attribute, and as an attribute in reference to a more basic subject. Nevertheless, this must not develop into an infinite process, for one must arrive at something which is first in that science and which is taken as a subject in such a way that it is never taken as a proper attribute, as is clear in the mathematical sciences, which treat of continuous or discrete quantity. For in these sciences those things are postulated which are first in the genus of quantity; for example, unit and line and surface and the like. Once these are postulated, certain other things are sought through demonstration, such as the equilateral triangle and the square and so on in geometry. In these cases the demonstrations are said to be, as it were, operational, as when it is required to construct an equilateral triangle on a given straight line. But once it has been constructed, certain proper attributes are proved about it; for example, that its angles are equal, or something of that sort. It is clear, therefore, that in the first type of demonstration “triangle” behaves as a proper attribute, and in the second type as a subject. Hence the Philosopher is using “triangle” as a proper attribute and not as a subject when he says by way of example, “We must assume that triangle means so and so” (71a14).
lib. 1 l. 2 n. 6 Dicit etiam quod quaedam sunt de quibus oportet praescire utrunque, scilicet quid est et quia est. Et exemplificat de unitate quae est principium in omni genere quantitatis. Etsi enim aliquo modo sit accidens respectu substantiae, tamen in scientiis mathematicis, quae sunt de quantitate, non potest accipi ut passio, sed ut subiectum tantum, cum in hoc genere nihil habeat prius.	He says, ‘furthermore, that there are certain things about which we must know beforehand both what each is and whether it is. And he uses the example of “one,” which is the principle in every genus of quantity. For although it is somehow an accident in reference to substance, yet in the mathematical sciences, which treat of quantity, it cannot be taken as a proper attribute but only as a subject, since in this genus [quantity] it has nothing prior to it.
lib. 1 l. 2 n. 7 Rationem autem huiusmodi diversitatis ostendit, quia non est similis modus manifestationis praedictorum, scilicet principii, passionis et subiecti. Non enim est eadem ratio cognitionis in ipsis: nam principia cognoscuntur per actum componentis et dividentis; subiectum autem et passio per actum apprehendentis quod quid est. Quod quidem non similiter competit subiecto et passioni: cum subiectum definiatur absolute, quia in definitione eius non ponitur aliquid, quod sit extra essentiam ipsius; passio autem definitur cum dependentia ad subiectum, quod in eius definitione ponitur. Unde, ex quo non eodem modo cognoscuntur, non est mirum si eorum diversa praecognitio sit.	The reason for this difference is shown by the fact that the manner in which the aforesaid, namely, principle, proper attribute and subject, are manifested is not the same. For the way in which they are known is not the same: for principles are known through the act of composing and dividing, but subject and proper attribute by the act of apprehending the essence. And this, too, does not belong in similar fashion to a subject and to a proper attribute, since a subject is defined absolutely, for nothing outside its essence is mentioned in its definition; but a proper attribute is defined with dependence on the subject which is mentioned in its definition. Therefore, since they are not known in the same way, it is not surprising if they are not foreknown in the same way.
lib. 1 l. 2 n. 8 Deinde cum dicit: est autem cognoscere etc., determinat modum praecognitionis ex parte ipsius ordinis, quem praecognitio importat. Est enim aliquid prius altero et secundum tempus et secundum naturam. Et hic duplex ordo in praecognitione considerandus est. Aliquid enim praecognoscitur sicut prius notum tempore. Et de his dicit quod alia contingit cognoscere aliquem cognoscentem ea prius tempore, quam illa quibus praecognosci dicuntur. Quaedam vero cognoscuntur simul tempore, sed prius natura. Et de his dicit quod quorundam praecognitorum simul tempore est accipere notitiam, et illorum quibus praecognoscuntur.	Then (7a16) he determines the extent of foreknowledge on the part of the order which foreknowing implies. For something is prior to another both in the order of time and in the order of nature. And this twofold order must be considered in regard to pre-existent knowing. For something is known before something else in the sense of being known prior in time. Concerning such things he says that someone could know certain things by knowing them prior to the time when he knows the things to which they are said to be foreknown. But certain others are known at one and the same time, although one is prior by nature to the other. Concerning these he says that one acquires a knowledge of some of these foreknown things at the same time that knowledge of the things to which they are foreknown is acquired.
lib. 1 l. 2 n. 9 Quae autem sint ista manifestat subdens quod huiusmodi sunt quaecumque continentur sub aliquibus universalibus, quorum habent cognitionem, idest de quibus notum est ea sub talibus universalibus contineri.	He indicates what these are when he adds that they are the things contained under certain universals of which we have knowledge, i.e., of which it is known that they are contained under such universals.
Et hoc ulterius manifestat per exemplum. Cum enim ad conclusionem inferendam duae propositiones requirantur, scilicet maior et minor, scita propositione maiori, nondum habetur conclusionis cognitio. Maior ergo propositio praecognoscitur conclusioni non solum natura, sed tempore. Rursus autem si in minori propositione inducatur sive assumatur aliquid contentum sub universali propositione, quae est maior, de quo manifestum non sit quod sub hoc universali contineatur, nondum habetur conclusionis cognitio, quia nondum erit certa veritas minoris propositionis. Si autem in minori propositione assumatur terminus, de quo manifestum sit quod continetur sub universali in maiori propositione, patet veritas minoris propositionis: quia id quod accipitur sub universali habet eius cognitionem, et sic statim habetur conclusionis cognitio. Ut si sic demonstraret aliquis, omnis triangulus habet tres angulos aequales duobus rectis, ista cognita, nondum habetur conclusionis cognitio: sed cum postea assumitur, haec figura descripta in semicirculo, est triangulus, statim scitur quod habet tres angulos aequales duobus rectis. Si autem non esset manifestum quod haec figura in semicirculo descripta est triangulus, nondum statim inducta assumptione sciretur conclusio; sed oporteret ulterius aliud medium quaerere, per quod demonstraretur hanc figuram esse triangulum.	Then he clarifies this with an example. For since two propositions are needed for inferring a conclusion, namely, a major and a minor; when the major proposition is known, the conclusion is not yet known. Therefore, the major proposition is known before the conclusion not only in nature but in time. Further, if in the minor proposition something is introduced or employed which is contained under the universal proposition which is the major, but it is not evident that it is contained under this universal, then a knowledge of the conclusion is not yet possessed, because the truth of the minor proposition will not yet be certain. But if in the minor proposition a term is taken about which it is clear that it is contained under the universal in the major proposition, the truth of the minor proposition is clear, because that which is taken under the universal shares in the same knowledge, and so the knowledge of the conclusion is had at once. Thus, suppose that someone should begin to demonstrate by stating that every triangle has three angles equal to two right angles. When this is known, the knowledge of the conclusion is not yet known. But when it is later assumed that this figure inscribed in a semicircle is a triangle, he knows at once that it has three angles equal to two right angles. However, if it were not clear that this figure inscribed in the semicircle is a triangle, the conclusion would not be known as soon as the minor was stated; rather, it would be necessary to search for a middle through which to demonstrate that this figure is a triangle.
Exemplificans ergo philosophus de his quae cognoscuntur ante conclusionem prius tempore, dicit quod aliquis per demonstrationem conclusionis cognitionem accipiens, hanc propositionem praescivit etiam secundum tempus, scilicet, quod omnis triangulus habet tres angulos duobus rectis aequales. Sed inducens hanc assumptionem, scilicet, quod hoc quod est in semicirculo sit triangulus, simul, scilicet tempore, cognovit conclusionem, quia hoc inductum habet notitiam universalis, sub quo continetur, ut non oporteat ulterius medium quaerere. Et ideo subdit quod, quorundam est hoc modo disciplina, idest eorum accipitur cognitio per se, et non oportet ea cognoscere per aliquod aliud medium, quod sit ultimum in resolutione, qua mediata ad immediata reducuntur. Vel potest legi sic: quod ultimum, idest extremum, quod accipitur sub universali medio, non oportet ut cognoscatur esse sub illo universali per aliquod aliud medium. Et quae sint ista, quae semper habent cognitionem sui universalis, manifestat subdens quod huiusmodi sunt singularia, quae non dicuntur de aliquo subiecto: cum inter singularia et speciem nullum medium possit inveniri.	In giving this example of things which are known at a time prior to the conclusion the Philosopher says that a person obtaining a knowledge of the conclusion through demonstration foreknew this proposition even according to time, namely, that every triangle has three angles equal to two right angles. But inducing this assumption, namely, that this figure in the semicircle is a triangle, he knew the conclusion at the same time, because this induction shares in the evidence of the universal under which it is contained, so that there is no need to search for another middle. He adds, therefore, that “some things are only learnt in this way” (71a23), i.e., learnt in virtue of themselves, so that it is not necessary to learn them through some other middle which is the ultimate reached by analysis in which the mediate is reduced to the immediate. Or it can be read in such a way that the “ultimate,” i.e., the extreme, which is subsumed under the universal middle does not need a further middle to show that it i contained under that universal. And he manifests what those things are which always share the knowledge of their universal, saying that they are the singulars, which are not predicated of any subject, since no middle can be found between singulars and their species.