Authors/Thomas Aquinas/metaphysics/liber11/lect1

Lecture 1

Latin	English
lib. 11 l. 1 n. 1 Quia particulares scientiae quaedam eorum quae perscrutatione indigent praetermittunt, necesse fuit quamdam scientiam esse universalem et primam, quae perscrutetur ea, de quibus particulares scientiae non considerant. Huiusmodi autem videntur esse tam communia quae sequuntur ens commune (de quibus nulla scientia particularis considerat, cum non magis ad unam pertineant quam ad aliam, sed ad omnes communiter), quam etiam substantiae separatae, quae excedunt considerationem omnium particularium scientiarum. Et ideo Aristoteles huiusmodi scientiam nobis tradens, postquam perscrutatus est de communibus, accedit ad tractandum specialiter de substantiis separatis, ad quarum cognitionem ordinantur non solum ea quae in hac scientia tractata sunt, sed etiam quae in aliis scientiis tractantur. Et ideo ad manifestiorem considerationem de substantiis separatis habendam, primo sub quodam compendio recolligit ea quae dicta sunt tam in hoc libro, quam in libro physicorum, utilia ad cognitionem substantiarum separatarum. Secundo de ipsis substantiis separatis inquirit, circa medietatem sequentis libri, ibi, sed quoniam tres sunt substantiae. Prima pars dividitur in duas. In prima recolligit ea quae praecedunt considerationem substantiae. In secunda recolligit ea quae ad considerationem substantiae pertinent, ibi (in principio sequentis libri), de substantia quidem theorica. Tria autem praemiserat ante considerationem substantiae. Primo moverat dubitationes in tertio libro, quas in hoc primo recolligit. Secundo determinaverat ea quae ad considerationem huius scientiae pertinent, in quarto libro, quae et hic secundo loco recolligit, ibi, quoniam autem philosophi scientia. Tertio determinat de ente imperfecto, scilicet de ente per accidens, et de motu, et infinito, et de quibus partim determinaverat in secundo et sexto huius, partim in tertio physicorum. Et de his in tertio loco hic recolligit, ibi, quoniam autem simpliciter ens et cetera. Prima pars dividitur in duas. Primo movet dubitationem circa considerationem huius scientiae. In secunda circa res, de quibus in hac scientia determinatur, ibi, adhuc unum oportet poni. Circa primum duo facit. Primo inquirit quomodo sit consideratio huius scientiae circa principia et substantias. Secundo circa quae principia, et circa quas substantias, ibi, sed nec circa dicta a physicis. Circa primum duo facit. Primo dubitationes movet de consideratione huius scientiae circa principia. Secundo de consideratione huius scientiae circa substantias, ibi, adhuc utrum omnium substantiarum. Circa primum tria facit. Primo supponit considerationem huius scientiae esse circa principia, dicens, quod manifestum est ex primo libro, in quo disputavit contra ea quae alii philosophi dixerunt de primis rerum principiis, quod sapientia est scientia quaedam circa principia. Ostensum est enim in prooemio istius libri, quod sapientia considerat causas altissimas et maxime universales, et est nobilissima scientiarum.	2146. Because the particular sciences disregard certain things which should be investigated, there must be a universal science which examines these things. Now such things seem to be the common attributes which naturally belong to being in general (none of which are treated by the particular sciences since they do not pertain to one science rather than to another but to all in general) and to the separate substances, which lie outside the scope of every particular science. Therefore, in introducing us to such knowledge, Aristotle, after he has investigated these attributes, begins to deal particularly with the separate substances, the knowledge of which constitutes the goal to which the things studied both in this science and in the other sciences are ultimately directed. Now in order that a clearer understanding of the separate substances may be had, Aristotle first (899:C 2146) makes a summary of the points discussed both in this work and in the Physics’ which are useful for knowing the separate substances. Second (1055:C 2488), he investigates the separate substances in themselves (in the middle of the following book: “Since there are”). The first part is divided into two. In the first he summarizes the points which act as a preface to the study of substances. In the second (1023:C 2416) he restates the things that pertain to the study of substances (at the beginning of the following book: “The study here”). He prefaced his study of substances by doing three things. First, he raised the questions given in Book 11, which he now restates under the first point of discussion. Second (924:C 2194), he expressed his views about the things that pertain to the study of this science. These are given in Book IV and are restated here under the second point of discussion (“Since the science”). Third (963:C 2268), he drew his conclusions about imperfect being, i.e., accidental being, motion, and the infinite, about which he had partly established the truth in Books II (152:C 299) and VI (543-59:C 1171-1244) of this work, and partly in Book III of the Physics; and he gives a summary restatement of these under the third point of discussion (“Since the term being”). The first part is divided into two. First, he raises a question about the study of this science; and second (912:C 2173), about the things established in this science (“Further, there is”). In regard to the first he does two things. First, he asks in what way the study of this science is concerned with principles and substances. Second (904: C 2156), he asks with what principles and what substances it deals (“But the science”). In regard to the first he does two things. First, he raises questions about the study of the principles of this science; and second (902:C 2152), about this science’s study of substances (“Further, there is the question”). In treating the first point (899) he does three things. First, he assumes that the investigations of this science are concerned with principles. He says that it is evident from Book I (45-143:C 93-272), in which he argued against the statements that other philosophers have made about the first principles of things, that wisdom is a science of principles. For it was shown in the Prologue to this work that wisdom considers the highest and most universal causes, and that it is the noblest of the sciences.
lib. 11 l. 1 n. 2 Secundo ibi, dubitabit autem movet quaestionem de consideratione huius scientiae quae sapientia dicitur, circa principia rerum; dicens quod aliquis potest dubitare, utrum oporteat sapientiam quae considerat principia, esse unam scientiam aut multas.	2147. But one might (900). Second, he raises a question about the study of the principles by this science which is called wisdom. He says that one can ask whether wisdom, which considers principles, must be one science or many.
lib. 11 l. 1 n. 3 Et si dicatur quod est una, videtur hoc esse in contrarium, quia plura, de quibus consideratur in una scientia, sunt contraria, eo quod unum contrariorum est ratio ad cognoscendum alterum, propter hoc videntur sub una arte cadere. Sed principia rerum, cum sint plura, non sunt contraria, alioquin non possent convenire in uno principiato. Sapientia ergo quae est de principiis, non videtur esse una scientia. Si vero dicatur quod non est una, sed plures, non est eas assignare.	2148. However, if we say that it is one, this seems to be inconsistent, because many of the things studied in one science are contraries, since one contrary is the basis for knowing the other, and thus both contraries seem to fall under one art. But since the principles of things are many, they are not contraries, otherwise they could not be combined in one subject. Hence, wisdom, which is concerned with principles, does not seem to be one science. And if it is not one science but many, it is impossible to state what these sciences are.
lib. 11 l. 1 n. 4 Est autem veritas quod sapientia est una scientia, quae tamen considerat plura principia, inquantum reducuntur ad unum genus, quia et hac ratione contraria sub una scientia cadunt, inquantum sunt unius generis.	2149. Now the truth of the matter is that, while wisdom is one science, it considers many principles inasmuch as they are reduced to one genus, because contraries fall under one science since they belong to one genus.
lib. 11 l. 1 n. 5 Tertio ibi, adhuc speculari movet dubitationem de consideratione huius scientiae circa principia demonstrationis; dicens, quod adhuc dubitabile est, utrum speculari principia demonstrativa, ut, omne totum est maius sua parte, et similia, sit unius scientiae, aut plurium. Et si dicatur quod unius, videtur difficile assignare, quare magis sit istius scientiae quam alicuius alterius, cum omnes scientiae communiter eis utantur. Si autem detur quod sit plurium scientiarum, videbitur difficile assignare plures scientias tales.	2150. Further, one might (901). Third, he raises a question about the study which this science makes of the principles of demonstration. He says that it is still a problem whether the study of the principles of demonstration (for example, every whole is greater than one of its parts, and the like) belongs to the study of one science or many. If one claims that such a study belongs to one science, it seems difficult to explain why it belongs to this science rather than to another, since all sciences make common use of these principles. But if one claims that it belongs to many sciences, it seems difficult to give many sitch sciences.
lib. 11 l. 1 n. 6 Est autem veritas, quod una scientia principaliter considerat ista principia, ad quam consideratio pertinet communium, qui sunt termini illorum principiorum, sicut ens et non ens, totum et pars, et alia huiusmodi; et ab ea aliae scientiae huiusmodi principia accipiunt.	2151. Now the truth of the matter is that there is one science which is chiefly concerned with these principles, and this is the one which investigates the common terms involved in these principles, such as being and non-being, whole and part, and the like; and the other sciences receive such principles from this science.
lib. 11 l. 1 n. 7 Deinde cum dicit adhuc utrum movet dubitationes de consideratione huius scientiae circa substantias. Et quaerit duo. Primo utrum haec scientia consideret de omnibus substantiis, aut non. Et si detur quod non, difficile est assignare de quibus substantiis consideret, et de quibus non. Et si detur quod de omnibus consideret, cum sit una, remanet dubium, quomodo eadem scientia possit esse de pluribus, cum una scientia sit unius.	2152. Further, there is (902). Then he raises questions about this science's study of substances; and there are two of these. First, he asks whether or not this science considers all substances. If one claims that it does not, it is difficult to indicate what substances it does consider and what not. And if one claims that it considers all substances, the question remains how one and the same science can deal with many substances, since each science treats of one thing.
lib. 11 l. 1 n. 8 Et veritas est, quod haec scientia est de omnibus substantiis, licet de quibusdam principalius, scilicet de substantiis separatis, inquantum omnes conveniunt in uno genere, quod est ens per se.	2153. The truth is that, although this science deals especially with the separate substances, it does treat all substances inasmuch as all belong to one common class of essential being.
lib. 11 l. 1 n. 9 Secundo ibi, adhuc utrum quaerit utrum demonstratio sit solum circa substantias, aut etiam circa accidentia. Si enim demonstratio proprie esset circa accidentia, quia ad demonstrationem pertinet concludere per se accidentia de substantiis, non erit demonstratio circa substantias. Sed si dicatur, quod alia demonstrativa scientia est substantiarum, et alia accidentium per se, quaerendum restat quae sit utraque earum, et si utraque earum sit digna nomine sapientiae. Quia ex una parte videtur quod illa quae circa accidentia sit sapientia, quia demonstratio proprie est accidentium, et demonstrativa scientia certissima est. Et sic videtur quod sapientia sit demonstrativa quae est circa accidentia. Ex alia parte videtur quod sit circa substantias; quia cum substantia sit prima in entibus, scientia quae est circa substantias videtur esse prima.	2154. Again, there is (903). Second, he asks whether there is demonstration only with regard to substances or also with regard to accidents; for, if demonstration, properly speaking, were concerned with accidents, there would be no demonstration with regard to substances, since it is the function of demonstration to infer the essential accidents of substances. But if one claims that there is one demon. strative science of substances and an. other of essential accidents, the question remains as to which science each of these is, and whether each is worthy of the name of wisdom. For, on the one hand, it does seem that the science which deals with accidents is wisdom, because demonstration is properly concerned with accidents, and demonstrative science is the most certain. Thus it seems that wisdom, which is a demonstrative science, deals with accidents But, on the other hand, it seems to deal with substances; for since substances are the primary kind of being, it seems that the science which treats of them is the primary science.
lib. 11 l. 1 n. 10 Est autem veritas quod sapientia substantias et accidentia considerat, inquantum conveniunt in ente, quod est eius subiectum; sed substantias principaliter, sicut per se prima entia, et de his accidentia demonstrat.	2155. Now the truth is that wisdom considers both substances and accidents inasmuch as they have being in common, which constitutes the subject of wisdom; but its demonstrations are concerned chiefly with substances, which are the primary kind of essential beings, and of these it demonstrates the accidents.
lib. 11 l. 1 n. 11 Deinde cum dicit sed non movet quaestiones magis speciales de consideratione huius scientiae. Et primo circa quas substantias sit consideratio huius scientiae. Secundo circa quae principia, ibi, dubitabit autem utique. Circa primum movet quatuor quaestiones. Et prima quaestio pertinet ad causas substantiarum sensibilium; dicens, quod non videtur ponendum hanc scientiam quam quaerimus, circa quatuor genera causarum, de quibus dictum est in libro physicorum; quia maxime videretur esse circa causam finalem, quae est potissima inter alias. Sed non videtur esse haec scientia circa id cuius gratia, idest circa causam finalem: quia finis habet rationem boni. Bonum autem consistit in operationibus, et in his quae sunt in motu. Unde in immobilibus, sicut in mathematicis, nihil demonstratur per causam finalem. Et manifestum est quod finis est quod primum movet. Movet enim efficientem. Primum autem movens non videtur esse in rebus immobilibus.	2156. But the science (904). Then he raises more specific questions about the study of this science. First (904:C 2156), he asks about the substances which this science considers; and second (909:C 2166), about the principles which it considers (“And one might”). In treating the first point he raises four questions. The first (904) has to do with the causes of sensible substances. He says that it does not seem that we should hold that the science which we are seeking is concerned with the four classes of causes discussed in the Physics, because it seems to deal especially with the final cause, which is the most important of all. But this science does not seem to deal with “the final cause,” or goal, because an end or goal has the nature of the good. Now the good relates to operations and to things which are in motion. Hence in the case of immovable things, such as the objects of mathematics, nothing is demonstrated by way of the final cause. It is also evident that the end is what first moves a thing, for it moves the efficient cause. But there does not seem to be a first cause of motion in the case of immovable things.
lib. 11 l. 1 n. 12 Est autem veritas, quod haec scientia considerat dicta genera causarum, et praecipue causam formalem et finalem. Et ulterius finis qui est primum movens, est omnino immobile, ut infra ostendetur.	2157. Now the truth of the matter is that this science considers the classes of causes mentioned, especially the formal and final cause. And furthermore, the end, which is the first cause of motion, is altogether immovable, as will be shown below (1069:C 2526).
lib. 11 l. 1 n. 13 Secundo ibi, totaliter autem movet quaestionem de consideratione substantiarum sensibilium; et quaerit, utrum haec scientia sit circa substantias sensibiles, aut non. Si enim sit circa substantias sensibiles, non videtur differre a scientia naturali: si autem circa alias substantias, difficile est assignare circa quas alias. Aut enim est circa species, idest circa ideas, quas Platonici posuerunt; aut est circa mathematica, quae etiam quidam posuerunt esse media inter ideas et substantias sensibiles, sicut sunt superficies, et lineae, et figurae, et alia huiusmodi. Sed manifestum est per superiores libros, quod species non sunt, idest ideae separatae, et de mathematicis statim quaeretur.	2158. And in general (905). Second, he raises a question about the study of sensible substances. He asks whether this science is concerned with sensible substances or not. For if it is concerned with them, it does not seem to differ from the philosophy of nature. But if it is concerned with other substances, it is difficult to state what these substances are. For it must deal with either “the separate Forms,” i.e., the Ideas, which the Platonists posited, or with the objects of mathematics, which some supposed to exist as an intermediate class of things between the Ideas and sensible substances, for example, surfaces, lines, figures and the like. But it is evident from the previous books that “separate Forms do not exist,” i.e., separate Ideas; and so he immediately raises the question about the objects of mathematics.
lib. 11 l. 1 n. 14 Est autem veritas huius quaestionis, quod ista scientia determinat de substantiis sensibilibus, inquantum sunt substantiae, non inquantum sunt sensibiles et mobiles. Hoc enim proprie pertinet ad naturalem. Sed propria consideratio huius scientiae est de substantiis, quae non sunt ideae, nec mathematica separata, sed primi motores, ut infra patebit.	2159. Now the true answer to this question is that this science deals with sensible substances inasmuch as they are substances, but not inasmuch as they are sensible and movable; for this latter belongs properly to the philosophy of nature. But the proper study of this science has to do with substances which are neither Ideas nor separate mathematical entities but primary movers, as will be seen below (1055:C 2488).
lib. 11 l. 1 n. 15 Tertio ibi, attamen dubitationem movet tertiam dubitationem ex incidenti. Quia enim dixerat manifestum esse quod non sunt species separatae, movet dubitationem de mathematicis, utrum sint separatae. Et ostendit primo quod non: quia si aliquis ponat species separatas, et mathematica separata praeter substantias sensibiles, quare non est ita in omnibus quae habent species, sicut in mathematicis? Ut sicut mathematica ponitur media inter species et sensibilia, quasi quaedam tertia entia praeter species et particularia quae sunt hic, ut linea mathematica praeter speciem lineae et lineam sensibilem, ita poneretur tertius homo, et tertius equus praeter auton, idest per se hominem, et per se equum, quae appellabant Platonici ideas, et equum et hominem singulares. Sed in his Platonici media non ponebant, sed solum in mathematicis.	2160. But nevertheless (906). Third, he raises a third difficulty as a secondary issue. For, since he had said that there are evidently no separate Forms, he poses the question whether the objects of mathematics are separate. First, he shows that they are not. For if one claims that there are separate Forms and separate mathematical entities over and above sensible substances, why is not the same thing true of all things which have Forms as is true of the objects of mathematics? So that just as the objects of mathematics are assumed “ to be intermediate between the separate Forms and sensible substances as a third class of things over and above the separate Forms and the singular things which exist here (for example, a mathematical line over and above the Form of a line and the perceptible line), in a similar fashion there should be a third man and a third “horse over and above man-in-himself and horse-in-itself” (i.e., the ideal man and the ideal horse, which the Platonists called Ideas) and individual men and horses. But the Platonists did not posit intermediates in such cases as these but only in that of the objects of mathematics.
lib. 11 l. 1 n. 16 Postea vero cum dicit si autem obiicit in contrarium: quia si non sunt mathematica separata, difficile est assignare circa quae mathematicae scientiae negocientur. Non enim negociari videntur circa sensibilia inquantum huiusmodi; quia in istis sensibilibus non sunt tales lineae et tales circuli, quales scientiae mathematicae quaerunt. Unde videtur necesse ponere quasdam lineas et quosdam circulos separatos.	2161. If, however (907). Then he argues on the other side of the question; for, if the objects of mathematics are not separate, it is difficult to indicate the things with which the mathematical sciences deal. For they do not seem to deal with sensible things as such, because no lines and circles such as the mathematical sciences investigate are found in sensible things. It seems necessary to hold, then, that there are certain separate lines and circles.
lib. 11 l. 1 n. 17 Est autem veritas, quod mathematica non sunt separata a sensibilibus secundum se, sed solum secundum rationem, ut supra ostensum est in sexto, et infra declarabitur.	2162. Now the truth of the matter is that the objects of mathematics are not separate from sensible things in being but only in their intelligible structure, as has been shown above in Book VI (537:C 1162) and will be considered below (919:C 2185).
lib. 11 l. 1 n. 18 Et quia hanc dubitationem ex incidenti interposuerat de separatione mathematicorum ea occasione, quia dixerat manifestum esse, quod species non sunt separatae: consequenter cum dicit, neque etiam circa mathematica, redit ad quaestionem principalem, qua quaerebatur circa quas substantias sit ista scientia. Et cum ostenderit quod non sit circa species, quia species non sunt separatae, nunc ostendit eadem ratione, quod non est circa mathematica, quia nec ipsa sunt separata, scilicet secundum esse. Sed non videtur esse circa sensibiles substantias, cum sint corruptibiles et in motu existentes.	2163. And since he had interjected as a secondary issue this difficulty about the separateness of the objects of mathematics because he had said that forms evidently are not separate, therefore when he says, “Nor is the science which we are now seeking concerned with the objects of mathematics,” he returns to the main question that was raised, namely, with what kind of substances this science deals. And since he had shown that it does not deal with separate Forms (for there are no separate Forms), he now shows by the same reasoning that it does not deal with the objects of mathematics; for neither are they separate in being. And it does not seem to deal with sensible substances, because these are destructible and in motion.
lib. 11 l. 1 n. 19 Est autem veritas huius quaestionis, quae supra posita est.	2164. The true answer to this question is the one given above.
lib. 11 l. 1 n. 20 Quartam dubitationem ponit ibi, totaliter autem et quaerit cuius scientiae sit dubitare de materia mathematicarum scientiarum, idest inquirere de quibus mathematicae considerent. Non enim hoc est scientiae naturalis, propter hoc quod totum negocium naturalis philosophiae est circa ea, quae habent in seipsis principium motus et quietis, quae naturalia dicuntur. Unde de hac dubitatione se non intromittit. Similiter etiam consideratio huius dubitationis non videtur pertinere ad illam scientiam, quae intendit de demonstratione et scientia mathematicorum, quae dicitur mathematica scientia; quia huiusmodi scientia praesupponit huiusmodi materiam, sive huiusmodi subiectum; et circa ipsum aliqua inquirit. Unde relinquitur quod ad hanc philosophiam pertineat considerare, de quo tractant scientiae mathematicae.	2165. And in general one might (908). Then he gives a fourth difficulty by asking to what science it belongs “to consider the problems about the matter of the mathematical sciences,” i.e., to investigate the things with which the mathematical sciences are concerned. This does not pertain to the philosophy of nature, because it is wholly concerned with those things which have in themselves a principle of rest and of motion and are called natural beings. Therefore he does not examine this problem. Similarly, the investigation of this problem does not seem to belong to that science which is called mathematical, which has as its aim the demonstration and knowledge of mathematical entities; for this kind of science presupposes matter of this sort or a subject of this sort, and some science does investigate this subject. It follows, then, that it is the business of this philosophical science to consider the things of which the mathematical sciences treat.
lib. 11 l. 1 n. 21 Deinde cum dicit dubitabit autem inquirit circa qualia principia sit consideratio huius scientiae. Et circa hoc movet tres quaestiones. Primo enim quaerit, utrum haec scientia sit circa principia, quae a quibusdam elementa dicuntur. Quod videtur ex hoc, quod omnes ponunt huiusmodi principia esse inexistentia, idest intrinseca composito. Et ita oportet ad cognitionem compositorum, quod ipsa cognoscantur. Sed ex alia ratione videtur, quod ista scientia sit magis universalium, quia omnis ratio et omnis scientia videtur esse universalium et non extremorum, idest particularium, ad quae divisio communium terminatur: et sic videtur, quod ista scientia maxime sit priorum generum.	2166. And one might (909). Then he asks what kind of principles this science investigates. In regard to this he raises three questions. First, he asks whether this science studies the principles which are called elements by some thinkers. This question seems to refer to the common supposition that principles of this kind are present in, i.e., intrinsic to, the composite, so that in order to know composite things these principles must be known. But from another point of view it seems that this science is concerned with more universal things, because every intelligible nature and every science seems to be “of universals and not of extremes,” i.e., not about the particular things in which the division of common genera terminates. Thus it seems that this science has to do especially with the first genera.
lib. 11 l. 1 n. 22 Et veritas est, quod haec scientia praecipue considerat communia; non tamen quod communia sint principia, sicut Platonici posuerunt. Considerat autem et principia intrinseca rerum, sicut materiam et formam.	2167. But the truth is that this science deals chiefly with common attributes, yet without making the common factors principles in a Platonic sense. However, it does consider the intrinsic principles of things—matter and form.
lib. 11 l. 1 n. 23 Secundo ibi, haec autem movet secundam dubitationem. Videtur enim ex una parte, quod unum et ens sint principia et genera, quia haec maxime videntur continere omnia suo ambitu communitatis. Et maxime videntur esse principia, quia sunt prima naturaliter, quia eis interemptis interimuntur alia. Omnia enim sunt ens et unum: unde si auferatur unum et ens, omnia alia auferuntur; sed non convertitur. Et sic videntur esse prima naturaliter, cum prius naturaliter dicatur a quo non convertitur consequentia essendi.	2168. And these would (910). Second, he raises the second problem. For, on the one hand, it seems that unity and being are principles and genera, because these most of all seem to contain all things within their general ambit. And they seem to be principles because they are first by nature; for when they are destroyed, other things are too; for everything is a being and one. Hence, if being and unity are destroyed, everything else is destroyed, but not the other way around.
lib. 11 l. 1 n. 24 Ex alia parte videtur, quod unum et ens non sint genera, et per consequens nec principia, si genera sunt principia. Nulla enim differentia participat actu genus; quia differentia sumitur a forma, genus autem a materia. Sicut rationale a natura intellectiva, animal a natura sensitiva. Forma autem non includitur in essentia materiae actu, sed materia est in potentia ad ipsam. Et similiter differentia non pertinet ad naturam generis, sed genus habet differentiam potestate. Et propter hoc differentia non participat genus; quia cum dico rationale, significo aliquid habens rationem. Nec est de intellectu rationalis quod sit animal. Illud autem participatur, quod est de intellectu participantis. Et propter hoc dicitur, quod differentia non participat genus. Nulla autem posset differentia sumi, de cuius intellectu non esset unum et ens. Unde unum et ens non possunt habere aliquas differentias. Et ita non possunt esse genera, cum omne genus habeat differentias.	2169. But, on the other hand, it seems that unity and being are not genera, and therefore they are not principles if genera are principles. For no difference participates actually in a genus, because difference is derived from form and genus from matter; for example, rational is taken from intellective nature, and animal from sensory nature. Now form is not included actually in the essence of matter, but matter is in potentiality to form. And similarly difference does not belong to the nature of a genus, but a genus contains differences potentially. And for this reason a difference does not participate in a genus, because, when I say “rational,” I signify something having reason. Nor does it belong to the intelligibility of rational that it should be animal. Now that is participated in which is included in the intelligibility of the thing which participates; and for this reason it is said that a difference does not participate in a genus. But there cannot be any difference whose intelligibility does not contain unity and being. Hence unity and being cannot have any differences. Thus, they cannot be genera, since every genus has differences.
lib. 11 l. 1 n. 25 Est autem veritas, quod unum et ens non sunt genera, sed sunt omnibus communia analogice.	2170. Now the truth of the matter is that unity and being are not genera but are common to all things analogically.
lib. 11 l. 1 n. 26 Tertiam quaestionem ponit ibi, adhuc autem et est dubitatio, utrum principia sint magis genera quam species. Et primo ostendit quod species magis sint principia quam genera; quia quod est simplicius, est magis principium. Sed species videntur esse simpliciores. Sunt enim indivisibilia, ad quae terminatur divisio generis formalis. Sed genera in plura et differentia specie dividuntur: ergo magis videntur principia esse species quam genera. Sed ex ea parte qua genera constituunt species, et non e converso, videntur genera esse magis principia. Hoc enim est de ratione principii, quod eo remoto alia removentur.	2171. Further, if what (911). Then he raises the third question. The problem now is whether genera are principles to a greater degree than species. First, he shows that species are principles to a greater degree than genera; for what is more simple is a principle to a greater degree. But species seem to be more simple, for they are the indivisible things in which the formal division of a genus terminates. But genera are divided into many different species, and therefore species seem to be principles to a greater degree than genera. But in view of the fact that genera constitute species, and not vice versa, genera seem to be principles to a greater degree; for the intelligible structure of a principle is such that, when it is destroyed, other things are destroyed.
lib. 11 l. 1 n. 27 Est autem veritas quod universalia sunt principia, scilicet in cognoscendo; et sic genera magis sunt principia, quia simpliciora. Et quod dividantur in plura quam species, hoc est, quia continent plura in potentia. Sed species continent plura in actu. Unde sunt magis divisibiles per modum resolutionis compositi in simplicia.	2172. Now the truth is that universals are principles, namely, of knowing; and thus genera are principles to a greater degree because they are simpler. The reason why they are divided into more members than species are is that they contain more members potentially. But species contain many members actually. Hence they are divisible to a greater degree by the method of dissolving a composite into its simple constituents.