Authors/Thomas Aquinas/physics/L1

LECTURE 1 THE MATTER AND THE SUBJECT OF NATURAL SCIENCE

Latin	English
Textum Leoninum Taurini 1954 editum	LECTURE 1 (184 a 9-b 14) THE MATTER AND THE SUBJECT OF NATURAL SCIENCE AND OF THIS BOOK. WE MUST PROCEED FROM THE MORE UNIVERSAL PRINCIPLES WHICH ARE BETTER KNOWN TO US
lib. 1 l. 1 n. 1 Quia liber physicorum, cuius expositioni intendimus, est primus liber scientiae naturalis, in eius principio oportet assignare quid sit materia et subiectum scientiae naturalis. Sciendum est igitur quod, cum omnis scientia sit in intellectu, per hoc autem aliquid fit intelligibile in actu, quod aliqualiter abstrahitur a materia; secundum quod aliqua diversimode se habent ad materiam, ad diversas scientias pertinent. Rursus, cum omnis scientia per demonstrationem habeatur, demonstrationis autem medium sit definitio; necesse est secundum diversum definitionis modum scientias diversificari.	1. Because this book, The Physics, upon which we intend to comment here, is the first book of natural science, it is necessary in the beginning to decide what is the matter and the subject of natural science. Since every science is in the intellect, it should be understood that something is rendered intelligible in act insofar as it is in some way abstracted from matter. And inasmuch as things are differently related to matter they pertain to different sciences. Furthermore, since every science is established through demonstration, and since the definition is the middle term in a demonstration, it is necessary that sciences be distinguished according to the diverse modes of definition.
lib. 1 l. 1 n. 2 Sciendum est igitur quod quaedam sunt quorum esse dependet a materia, nec sine materia definiri possunt: quaedam vero sunt quae licet esse non possint nisi in materia sensibili, in eorum tamen definitione materia sensibilis non cadit. Et haec differunt ad invicem sicut curvum et simum. Nam simum est in materia sensibili, et necesse est quod in eius definitione cadat materia sensibilis, est enim simum nasus curvus; et talia sunt omnia naturalia, ut homo, lapis: curvum vero, licet esse non possit nisi in materia sensibili, tamen in eius definitione materia sensibilis non cadit; et talia sunt omnia mathematica, ut numeri, magnitudines et figurae. Quaedam vero sunt quae non dependent a materia nec secundum esse nec secundum rationem; vel quia nunquam sunt in materia, ut Deus et aliae substantiae separatae; vel quia non universaliter sunt in materia, ut substantia, potentia et actus, et ipsum ens.	2. It must be understood, therefore, that there are some things whose existence depends upon matter, and which cannot be defined without matter. Further there are other things which, even though they cannot exist except in sensible matter, have no sensible matter in their definitions. And these differ from each other as the curved differs from the snub. For the snub exists in sensible matter, and it is necessary that sensible matter fall in its definition, for the snub is a curved nose. And the same is true of all natural things, such as man and stone. But sensible matter does not fall in the definition of the curved, even though the curved cannot exist except in sensible matter. And this is true of all the mathematicals, such as numbers, magnitudes and figures. Then, there are still other things which do not depend upon matter either according to their existence or according to their definitions. And this is either because they never exist in matter, such as God and the other separated substances, or because they do not universally exist in matter, such as substance, potency and act, and being itself.
lib. 1 l. 1 n. 3 De huiusmodi igitur est metaphysica: de his vero quae dependent a materia sensibili secundum esse sed non secundum rationem, est mathematica: de his vero quae dependent a materia non solum secundum esse sed etiam secundum rationem, est naturalis, quae physica dicitur. Et quia omne quod habet materiam mobile est, consequens est quod ens mobile sit subiectum naturalis philosophiae. Naturalis enim philosophia de naturalibus est; naturalia autem sunt quorum principium est natura; natura autem est principium motus et quietis in eo in quo est; de his igitur quae habent in se principium motus, est scientia naturalis.	3. Now metaphysics deals with things of this latter sort. Whereas mathematics deals with those things which depend upon sensible matter for their existence but not for their definitions. And natural science, which is called physics, deals with those things which depend upon matter not only for their existence, but also for their definition. And because everything which has matter is mobile, it follows that mobile being is the subject of natural philosophy. For natural philosophy is about natural things, and natural things are those whose principle is nature. But nature is a principle of motion and rest in that in which it is. Therefore natural science deals with those things which have in them a principle of motion.
lib. 1 l. 1 n. 4 Sed quia ea quae consequuntur aliquod commune, prius et seorsum determinanda sunt, ne oporteat ea multoties pertractando omnes partes illius communis repetere; necessarium fuit quod praemitteretur in scientia naturali unus liber, in quo tractaretur de iis quae consequuntur ens mobile in communi; sicut omnibus scientiis praemittitur philosophia prima, in qua determinatur de iis quae sunt communia enti inquantum est ens. Hic autem est liber physicorum, qui etiam dicitur de physico sive naturali auditu, quia per modum doctrinae ad audientes traditus fuit: cuius subiectum est ens mobile simpliciter. Non dico autem corpus mobile, quia omne mobile esse corpus probatur in isto libro; nulla autem scientia probat suum subiectum: et ideo statim in principio libri de caelo, qui sequitur ad istum, incipitur a notificatione corporis. Sequuntur autem ad hunc librum alii libri scientiae naturalis, in quibus tractatur de speciebus mobilium: puta in libro de caelo de mobili secundum motum localem, qui est prima species motus; in libro autem de generatione, de motu ad formam et primis mobilibus, scilicet elementis, quantum ad transmutationes eorum in communi; quantum vero ad speciales eorum transmutationes, in libro Meteororum; de mobilibus vero mixtis inanimatis, in libro de mineralibus; de animatis vero, in libro de anima et consequentibus ad ipsum.	4. Furthermore those things which are consequent upon something common must be treated first and separately. Otherwise it becomes necessary to repeat such things many times while discussing each instance of that which is common. Therefore it was necessary that one book in natural science be set forth in which those things which are consequent upon mobile being in common are treated; just as first philosophy, in which those things which are common to being insofar as it is being, is set forth for all the sciences. This, then, is the book, The Physics, which is also called On Physics, or Of the Natural to be Heard, because it was handed down to hearers by way of instruction. And its subject is mobile being simply. I do not, however, say mobile body, because the fact that every mobile being is a body is proven in this book, and no science proves its own subject. And thus in the very beginning of the De Caelo, which follows this book, we begin with the notion of body. Moreover, after The Physics there are other books of natural science in which the species of motion are treated. Thus in the De Caelo we treat the mobile according to local motion, which is the first species of motion. In the De Generatione, we treat of motion to form and of the first mobile things, i.e., the elements, with respect to the common aspects of their changes. Their special changes are considered in the book Meteororum. In the book, De Mineralibus, we consider the mobile mixed bodies which are non-living. Living bodies are considered in the book, De Anima and the books which follow it.
lib. 1 l. 1 n. 5 Huic autem libro praemittit philosophus prooemium, in quo ostendit ordinem procedendi in scientia naturali. Unde duo facit: primo ostendit quod oportet incipere a consideratione principiorum; secundo quod inter principia oportet incipere a principiis universalioribus, ibi: innata autem et cetera. Primo ergo ponit talem rationem. In omnibus scientiis quarum sunt principia aut causae aut elementa, intellectus et scientia procedit ex cognitione principiorum, causarum et elementorum; sed scientia quae est de natura, habet principia, elementa et causas; ergo in ea oportet incipere a determinatione principiorum. Quod autem dicit intelligere, refertur ad definitiones; quod vero dicit scire, ad demonstrationes. Nam sicut demonstrationes sunt ex causis, ita et definitiones; cum completa definitio sit demonstratio sola positione differens, ut dicitur in I Poster. Per hoc autem quod dicit principia aut causas aut elementa, non intendit idem significare. Nam causa est in plus quam elementum; elementum enim est ex quo componitur res primo et est in eo, ut dicitur in V Metaphys., sicut litterae sunt elementa locutionis, non autem syllabae: causae autem dicuntur ex quibus aliqua dependent secundum suum esse vel fieri; unde etiam quae sunt extra rem, vel quae sunt in re ex quibus non componitur res primo, possunt dici causae, non tamen elementa. Principium vero importat quendam ordinem alicuius processus; unde aliquid potest esse principium, quod non est causa: sicut id unde incipit motus est principium motus, non tamen causa; et punctum est principium lineae, non tamen causa. Sic igitur per principia videtur intelligere causas moventes et agentes, in quibus maxime attenditur ordo processus cuiusdam; per causas autem videtur intelligere causas formales et finales, a quibus maxime dependent res secundum suum esse et fieri; per elementa vero proprie primas causas materiales. Utitur autem istis nominibus disiunctim et non copulatim ad designandum quod non omnis scientia per omnes causas demonstrat. Nam mathematica non demonstrat nisi per causam formalem; metaphysica demonstrat per causam formalem et finalem praecipue, et etiam agentem; naturalis autem per omnes causas. Primam autem propositionem rationis inductae probat ex communi opinione, sicut et in libro Poster.: quia tunc quilibet opinatur se cognoscere aliquid, cum scit omnes causas eius a primis usque ad ultimas. Nec oportet ut aliter accipiamus hic causas et elementa et principia quam supra, ut Commentator vult, sed eodem modo. Dicit autem usque ad elementa, quia id quod est ultimum in cognitione est materia. Nam materia est propter formam; forma autem est ab agente propter finem, nisi ipsa sit finis: ut puta dicimus quod propter secare serra habet dentes, et ferreos oportet eos esse ut sint apti ad secandum.	5. To this book, then, the Philosopher writes a preface in which he shows the order of procedure in natural science. In this preface he does two things. First he shows that it is necessary to begin with a consideration of principles. Secondly, where he says, ‘The natural way of doing this...’ (184 a 16), he shows that among principles, it is necessary to begin with the more universal principles. First he gives the following argument. In all sciences of which there are principles or causes or elements, understanding and science proceed from a knowledge of the principles, causes and elements. But the science which is about nature has principles, elements and causes. Therefore it is necessary in it to begin with a determination of principles. When he says ‘to understand’ he has reference to definitions, and when he says ‘to have science’ he has reference to demonstrations. For as demonstrations are from causes, so also are definitions, since a complete definition is a demonstration differing only by position, as is said in Posterior Analytics, I:8. When, however, he speaks of principles or causes or elements, he does not intend to signify the same thing by each. For cause is wider in meaning than element. An element is a first component of a thing and is in it [i.e., in the composed], as is said in Metaphysics, V:3. Thus the letters, but not the syllables, are the elements of speech. But those things are called causes upon which things depend for their existence or their coming to be. Whence even that which is outside the thing, or that which is in it, though the thing is not first composed of it, can be called a cause. But it cannot be called an element. And thirdly principle implies a certain order in any progression. Whence something can be a principle which is not a cause, as that from which motion begins is a principle of motion, but is not a cause, and a point is a principle of a line but not a cause. Therefore, by principle he seems to mean moving causes and agents in which, more than in others, there is found an order of some progression. By causes he seems to mean formal and final causes upon which things most of all depend for their existence and their coming to be. By elements he means properly the first material causes. Moreover he uses these terms disjunctively and not copulatively in order to point out that not every science demonstrates through. all the causes. For mathematics demonstrates only through the formal cause. Metaphysics demonstrates through the formal and final causes principally but also through the agent. Natural science, however, demonstrates through all the causes. He then proves from common opinion the first proposition of his argument. This is also proven in the Posterior Analytics I:2. For a man thinks that he knows something when he knows all its causes from the first to the last. The meaning here of causes, principles, and elements is exactly the same as we have explained above, even though the Commentator disagrees. Furthermore Aristotle says, ‘...as far as its simplest elements’ (184 a 14), because that which is last in knowledge is matter. For matter is for the sake of form, and form is from the agent for the sake of the end, unless it itself is the end. For example, we say that a saw has teeth in order to cut, and these teeth ought to be made of iron so they will be apt for cutting.
lib. 1 l. 1 n. 6 Deinde cum dicit: innata autem etc., ostendit quod inter principia oportet praedeterminare de universalioribus: et primo ostendit hoc per rationem; secundo per quaedam signa, ibi: totum enim et cetera. Circa primum ponit talem rationem. Innatum est nobis ut procedamus cognoscendo ab iis quae sunt nobis magis nota, in ea quae sunt magis nota naturae; sed ea quae sunt nobis magis nota, sunt confusa, qualia sunt universalia; ergo oportet nos ab universalibus ad singularia procedere.	6. Next where he says, ‘The natural way of doing this...’(184 a 16), he shows that among principles it is necessary to treat the more universal ones first, And he shows this first by means of an argument, and secondly, by an “ample, where he says, for it is a whole (184 a 25 #9). First he gives the following argument. It is natural for us to proceed in knowing from those things which are better known to us to those which are better known by nature. But the things which are better known to us are confused, such as the universals. Therefore it is necessary for us to proceed from universals to singulars.
lib. 1 l. 1 n. 7 Ad manifestationem autem primae propositionis, inducit quod non sunt eadem magis nota nobis et secundum naturam; sed illa quae sunt magis nota secundum naturam, sunt minus nota secundum nos. Et quia iste est naturalis modus sive ordo addiscendi, ut veniatur a nobis notis ad ignota nobis; inde est quod oportet nos devenire ex notioribus nobis ad notiora naturae. Notandum autem est quod idem dicit nota esse naturae et nota simpliciter. Simpliciter autem notiora sunt, quae secundum se sunt notiora. Sunt autem secundum se notiora, quae plus habent de entitate: quia unumquodque cognoscibile est inquantum est ens. Magis autem entia sunt, quae sunt magis in actu: unde ista maxime sunt cognoscibilia naturae. Nobis autem e converso accidit, eo quod nos procedimus intelligendo de potentia in actum; et principium cognitionis nostrae est a sensibilibus, quae sunt materialia, et intelligibilia in potentia: unde illa sunt prius nobis nota quam substantiae separatae, quae sunt magis notae secundum naturam, ut patet in II Metaphys. Non ergo dicit notiora naturae, quasi natura cognoscat ea; sed quia sunt notiora secundum se et secundum propriam naturam. Dicit autem notiora et certiora, quia in scientiis non quaeritur qualiscumque cognitio, sed cognitionis certitudo. Ad intellectum autem secundae propositionis, sciendum est quod confusa hic dicuntur quae continent in se aliqua in potentia et indistincte. Et quia cognoscere aliquid indistincte, medium est inter puram potentiam et actum perfectum, ideo, dum intellectus noster procedit de potentia in actum, primo occurrit sibi confusum quam distinctum; sed tunc est scientia completa in actu, quando pervenitur per resolutionem ad distinctam cognitionem principiorum et elementorum. Et haec est ratio quare confusa sunt primo nobis nota quam distincta. Quod autem universalia sint confusa manifestum est, quia universalia continent in se suas species in potentia, et qui scit aliquid in universali scit illud indistincte; tunc autem distinguitur eius cognitio, quando unumquodque eorum quae continentur potentia in universali, actu cognoscitur: qui enim scit animal, non scit rationale nisi in potentia. Prius autem est scire aliquid in potentia quam in actu: secundum igitur hunc ordinem addiscendi quo procedimus de potentia in actum, prius quoad nos est scire animal quam hominem.	7. For purposes of clarifying the first proposition he makes the point that things which are better known to us and things which are better known according to nature are not the same. Rather those things which are better known according to nature are less known to us. And because the natural way or order of learning is that we should come to that which is unknown by us from that which is known by us, it is necessary for us to arrive at the better known in nature from the better known to us. It must be noted, however, that that which is known by nature and that which is known simply mean the same. Those things are better known simply which are in themselves better known. But those things are better known in themselves which have more being, because each thing is knowable insofar as it is being. However, those beings are greater which are greater in act. Whence these are the most knowable by nature. For us, however, the converse is true because we proceed in understanding from potency to act. Our knowledge begins from sensible things which are material and intelligible in potency. Whence these things are known by us before the separated substances, which are better known according to nature, as is clear in Metaphysics, II:2. He does not, therefore, say known by nature as if nature knew these things, but because they are better known in themselves and according to their proper natures. And he says better known and more certain, because in the sciences not just any kind of knowledge is sought, but a certain knowledge. Next in order to understand the second proposition, it must be known that those things are here called ‘confused’ which contain in themselves something potential and indistinct. And because to know something indistinctly is a mean between pure potency and perfect act, so it is that while our intellect proceeds from potency to act, it knows the confused before it knows the distinct. But it has complete science in act when it arrives, through resolution, at a distinct knowledge of the principles and elements. And this is the reason why the confused is known by us before the distinct. That universals are confused is clear. For universals contain in themselves their species in potency. And whoever knows something in the universal knows it indistinctly. The knowledge, however, becomes distinct when each of the things which are contained in potency in the universal is known in act. For he who knows animal does not know the rational except in potency. Thus knowing something in potency is prior to knowing it in act. Therefore, according to this order of learning, in which we proceed from potency to act, we know animal before we know man.
lib. 1 l. 1 n. 8 Contrarium autem huic videtur esse quod dicit philosophus in I Poster., quod singularia sunt magis nota quoad nos, universalia vero naturae sive simpliciter. Sed intelligendum est quod ibi accipit singularia ipsa individua sensibilia: quae sunt magis nota quoad nos, quia sensus cognitio, quae est singularium, praecedit cognitionem intellectus in nobis, quae est universalium. Sed quia cognitio intellectualis est perfectior, universalia autem sunt intelligibilia in actu, non autem singularia (cum sint materialia); simpliciter et secundum naturam universalia sunt notiora. Hic autem singularia dicit non ipsa individua, sed species; quae sunt notiores secundum naturam, utpote perfectiores existentes et distinctam cognitionem habentes: genera vero sunt prius nota quoad nos, utpote habentia cognitionem in potentia et confusam. Sciendum autem quod Commentator aliter exponit. Dicit enim quod ibi, innata autem est etc., vult ostendere philosophus modum demonstrationis huius scientiae, quia scilicet demonstrat per effectus et posteriora secundum naturam: ut sic quod ibi dicitur, intelligatur de processu in demonstrando, et non in determinando. Cum autem dicit, sunt autem nobis etc., intendit manifestare, secundum eum, quae sunt magis nota quoad nos et minus nota secundum naturam, scilicet composita simplicibus, intelligens composita per confusa. Ultimo autem concludit quod procedendum est ab universalioribus ad minus universalia, quasi quoddam corollarium. Unde patet quod eius expositio non est conveniens, quia non coniungit totum ad unam intentionem; et quia hic non intendit philosophus ostendere modum demonstrationis huius scientiae, hoc enim faciet in secundo libro secundum ordinem determinandi; iterum quia confusa non debent exponi composita, sed indistincta; non enim posset concludi aliquid ex universalibus, cum genera non componantur ex speciebus.	8. It would seem, however, that this is contrary to what the Philosopher says in Posterior Analytics, I:2, namely, that singulars are better known to us, whereas the universals are better known by nature or simply. But it must be understood that there he takes as singulars the individual sensible things themselves, which are better known to us because the knowledge of sense, which is of singulars, does precede in us the knowledge of the intellect, which is of universals. And because intellectual knowledge is more perfect, and because the universals are intelligible in act, whereas the singulars are not (since they are material), the universals are better known simply and according to nature. Here, however, by singulars he means not the individuals themselves, but the species. And these are better known by nature, existing more perfectly, as it were, and being known with a distinct knowledge. But the genera are known by us first, being known, as it were, confusedly and in potency. It should be known, however, that the Commentator explains this passage in another way. He says that in the passage beginning, ‘The natural way of doing this...’ (184 a 16), the Philosopher wishes to explain the method of demonstration of this science, namely, that this science demonstrates through the effect and what is posterior according to nature. Hence what is said here is to be understood of the progression in demonstration and not of the progression in determination. Then in the passage where Aristotle says, ‘Now what is plain to us...’(184 a 22), he intends to make clear (according to the Commentator) what things are better known to us and what is better known by nature, i.e., things which are composed of the simple, understanding ‘confused’ to mean ‘composed’. Finally, then, he concludes, as if to a corollary, that we must proceed from the more universal to the less universal. It is clear that his explanation is not suitable, because he does not join the whole passage to one intention. Moreover the Philosopher does not intend to set forth the mode of demonstration of this science here, because he will do this in Book II according to his order of treatment. Furthermore, the confused should not be taken to mean composed, but rather to mean indistinct. For nothing could be concluded from such universals because genera are not composed of species.
lib. 1 l. 1 n. 9 Deinde cum dicit: totum enim etc., manifestat propositum per tria signa. Quorum primum sumitur a toto integrali sensibili: et dicit quod totum sensibile est notius secundum sensum; ergo et totum intelligibile est notius secundum intellectum. Universale autem est quoddam totum intelligibile, quia comprehendit multa ut partes, scilicet sua inferiora; ergo universale est notius secundum intellectum quoad nos. Videtur autem haec probatio inefficax, quia utitur toto et parte et comprehensione aequivoce. Dicendum est autem quod totum integrale et universale conveniunt in hoc, quod utrumque est confusum et indistinctum. Sicuti enim qui apprehendit genus, non apprehendit species distincte sed in potentia tantum, ita qui apprehendit domum, nondum distinguit partes: unde cum ratione confusionis totum sit prius cognitum quoad nos, eadem ratio est de utroque toto. Esse autem compositum non est commune utrique toti: unde manifestum est quod signanter dixit supra confusa, et non composita.	9. Next, where he says, ‘... for it is a whole ...’ (184 a 25), he clarifies his position with three examples. The first of these is taken from the integral sensible whole. He says that since the sensible whole is better known to the sense, then, the intelligible whole is also better known to the intellect. But the universal is a sort of intelligible whole, because it comprehends many as parts, namely, its inferiors. Therefore the universal is better known to us intellectually. But it would seem that this proof is not effective, because he uses whole and part and comprehension equivocally. However it must be said that the integral whole and the universal agree in that each is confused and indistinct. For just as he who apprehends a genus does not apprehend the species distinctly, but in potency only, so also he who apprehends a house does not yet distinguish its parts. Whence it is that a whole is first known to us as confused. This applies to both of these wholes. However, to be composed is not common to each whole. Whence it is clear that Aristotle significantly said ‘confused’ above and not ‘composed’.
lib. 1 l. 1 n. 10 Deinde cum dicit: sustinent autem etc., ponit aliud signum de toto integrali intelligibili. Definitum enim se habet ad definientia quodammodo ut totum integrale, inquantum actu sunt definientia in definito; sed tamen qui apprehendit nomen, ut puta hominem aut circulum, non statim distinguit principia definientia; unde nomen est sicut quoddam totum et indistinctum, sed definitio dividit in singularia, idest distincte ponit principia definiti. Videtur autem hoc esse contrarium ei quod supra dixit; nam definientia videntur esse universaliora, quae dixit prius esse nota nobis. Item si definitum esset notius nobis quam definientia, non notificaretur nobis definitum per definitionem: nihil enim notificatur nobis nisi ex magis notis nobis. Sed dicendum quod definientia secundum se sunt prius nota nobis quam definitum; sed prius est notum nobis definitum, quam quod talia sint definientia ipsius: sicut prius sunt nota nobis animal et rationale quam homo; sed prius est nobis notus homo confuse, quam quod animal et rationale sint definientia ipsius.	10. Next where he says, ‘Much the same thing ...’ (184 b 9), he gives another example taken from the integral intelligible whole. For that which is defined is related to the things defining it as a kind of integral whole, insofar as the things defining it are in act in that which is defined. But he who apprehends a name, for example, man or circle, does not at once distinguish the defining principles. Whence it is that the name is, as it were, a sort of whole and is indistinct, whereas the definition divides into singulars, i.e., distinctly sets forth the principles of that which is defined. This, however, seems to be contrary to what he said above. For the things which define would seem to be more universal, and these, he said, were first known by us. Furthermore, if that which is defined were better known to us than the things which define, we would not grasp that which is defined through the definition, for we grasp nothing except through that which is better known to us. But it must be said that the things which define are in themselves known to us before that which is defined, but we know the thing which is defined before we know that these are the things which define it. Thus we know animal and rational before we know man. But man is known confusedly before we know that animal and rational are the things which define man.
lib. 1 l. 1 n. 11 Deinde cum dicit: et pueri etc., ponit tertium signum sumptum ex universaliori sensibili. Sicut enim universalius intelligibile est prius notum nobis secundum intellectum, ut puta animal homine, ita communius sensibile est prius notum nobis secundum sensum, ut puta hoc animal quam hic homo. Et dico prius secundum sensum et secundum locum et secundum tempus. Secundum locum quidem, quia cum aliquis a remotis videtur, prius percipimus ipsum esse corpus quam esse animal, et hoc prius quam quod sit homo, et ultimo quod sit Socrates. Et similiter secundum tempus puer prius apprehendit hunc ut quendam hominem, quam ut hunc hominem qui est Plato, qui est pater eius: et hoc est quod dicit, pueri primum appellant omnes viros patres et feminas matres, sed posterius determinant, idest determinate cognoscunt, unumquodque. Ex quo manifeste ostenditur quod prius cognoscimus aliquid sub confusione quam distincte.	11. Next where he says, ‘Similarly a child ...’ (184 b 11), he gives the third example taken from the more universal sensible. For as the more universal intelligible is first known to us intellectually, for example, animal is known before man, so the more common sensible is first known to us according to sense, for example, we know this animal before we know this man. And I say first according to sense both with reference to place and with reference to time. This is true according to place because, when someone is seen at a distance, we perceive him to be a body before we perceive that he is an animal, and animal before we perceive him to be a man, and finally we perceive that he is Socrates. And in the same way with reference to time, a boy apprehends this individual as some man before he apprehends this man, Plato, who is his father. And this is what he says: children at first call all men fathers and all women mothers, but later they determine, that is, they know each determinately. From this it is clearly shown that we know a thing confusedly before we know it distinctly.

LECTURE 2 THE OPINIONS OF THE ANCIENT PHILOSOPHERS ABOUT THE PRINCIPLES OF NATURE

Latin	English
	LECTURE 2 (184 b 15-185 a 19) THE OPINIONS OF THE ANCIENT PHILOSOPHERS ABOUT THE PRINCIPLES OF NATURE AND OF BEINGS. IT DOES NOT PERTAIN TO NATURAL SCIENCE TO DISPROVE SOME OF THESE OPINIONS
lib. 1 l. 2 n. 1 Posito prooemio, in quo ostensum est quod scientia naturalis debet incipere a principiis universalioribus, hic secundum praedictum ordinem incipit prosequi ea quae pertinent ad scientiam naturalem. Et dividitur in duas partes: in quarum prima determinat de principiis universalibus scientiae naturalis; in secunda determinat de ente mobili in communi, de quo intendit in hoc libro; et hoc in tertio libro, ibi: quoniam autem natura est et cetera. Prima in duas: in prima determinat de principiis subiecti huius scientiae, idest de principiis entis mobilis inquantum huiusmodi; in secunda de principiis doctrinae, in secundo libro, ibi: eorum quae sunt et cetera. Prima autem in duas: in prima prosequitur opiniones aliorum de principiis communibus entis mobilis; in secunda inquirit veritatem de eis, ibi: omnes igitur contraria principia et cetera. Circa primum tria facit: primo ponit diversas opiniones antiquorum philosophorum de principiis communibus naturae; secundo ostendit quod aliquas earum prosequi non pertinet ad naturalem, ibi: id quidem igitur etc.; tertio prosequitur opiniones improbando earum falsitatem, ibi: principium autem et cetera. Circa primum duo facit: primo ponit diversas opiniones philosophorum de principiis naturae; secundo ostendit eandem diversitatem esse circa opiniones philosophorum de entibus, ibi: similiter autem quaerunt et cetera.	12. Having completed the preface in which it was shown that natural science ought to begin with the more universal principles, here, according to the order already stated, he begins to pursue those matters which pertain to natural science. This discussion is divided into two parts. In the first part he treats the universal principles of natural science. In the second part he treats mobile being in common (which is what he intends to treat in this book).’ This is taken up in Book III, where he says, ‘Nature has been defined ...’ (200 b 12; L1). The first part is divided into two parts. First he treats the principles of the subject of this science, that is, the principles of mobile being as such. Secondly he treats the principles of the doctrine. This he does in Book II, where he says, ‘Of things that exist...’ (192 b 8; L1). The first part is divided into two parts. First he considers the opinions others have had concerning the common principles of mobile being. Secondly he seeks the truth concerning them, where he says, ‘All thinkers, then, agree ...’ (188 a 19; L10). Concerning the first part he makes three points. First he sets forth the different opinions of the ancient philosophers concerning the common principles of nature. Secondly, where he says, ‘Now to investigate ...’ (184 b 25 #15), he shows that it does not pertain to natural science to pursue some of these opinions. Thirdly, where he says, ‘The most pertinent question...’ (185 a 20; L3), he considers these opinions, showing their falsity. Concerning the first part he makes two points. First he sets forth the different opinions of the philosophers concerning the principles of nature. Secondly, where he says, ‘A similar inquiry is made ...’ (184 b 23 #14), he shows that this same diversity exists with reference to the opinions of the philosophers concerning beings.
lib. 1 l. 2 n. 2 Dicit ergo primo quod necesse est esse unum principium naturae aut multa; et utraque pars habuit philosophos opinantes. Quidam enim eorum posuerunt unum principium, quidam multa. Et eorum qui posuerunt unum, quidam posuerunt illud esse immobile, sicut Parmenides et Melissus, de quorum opinione infra patebit; quidam vero posuerunt illud esse mobile, scilicet antiqui naturales. Quorum quidam posuerunt aerem esse principium omnium naturalium, ut Diogenes; quidam vero aquam, ut Thales; quidam vero ignem, ut Heraclitus; alii vero aliquid medium inter aerem et aquam, ut vaporem. Nullus vero eorum qui posuerunt principium unum tantum, dixit illud esse terram, propter eius grossitiem. Huiusmodi autem principia mobilia dicebant, quia per horum alicuius rarefactionem et condensationem alia fieri dicebant. Eorum vero qui posuerunt plura principia, quidam posuerunt ea finita, quidam posuerunt infinita. Eorum autem qui posuerunt ea esse finita, licet plura uno, quidam posuerunt ea esse duo, scilicet ignem et terram, ut infra dicet de Parmenide; quidam vero tria, scilicet ignem, aerem et aquam (nam terram quasi compositam existimabant propter eius grossitiem); alii vero posuerunt ea esse quatuor, scilicet Empedocles, vel etiam secundum aliquem alium numerum (quia et ipse Empedocles cum quatuor elementis posuit duo alia, scilicet amicitiam et litem). Qui vero posuerunt plura infinita, diversificati sunt. Democritus enim posuit indivisibilia corpora quae dicuntur atomi, esse principia omnium rerum. Sed huiusmodi corpora posuit esse omnia unius generis secundum naturam, sed tamen differebant secundum figuram et formam: et non solum differebant, sed contrarietatem ad invicem habebant. Ponebat enim tres contrarietates, unam secundum figuram, quae est inter curvum et rectum; aliam secundum ordinem, quae est prioris et posterioris; aliam secundum positionem, scilicet ante et retro, sursum et deorsum, dextrorsum et sinistrorsum. Et sic ex illis corporibus unius naturae existentibus, diversa fieri ponebat secundum diversitatem figurae, positionis et ordinis atomorum. Ex hac autem opinione dat intelligere oppositam opinionem, scilicet Anaxagorae, qui posuit infinita principia, sed non unius generis secundum naturam. Posuit enim principia naturae esse infinitas partes minimas carnis et ossis et aliorum huiusmodi, ut manifestum erit inferius. Attendendum autem quod non divisit plura principia per mobilia et immobilia, quia nullus ponens prima principia plura, potuit ponere ea immobilia: cum enim omnes ponerent contrarietatem in principiis, contraria autem nata sunt se alterare, cum pluralitate principiorum immobilitas stare non poterat.	13. He says, therefore, first of all, that it is necessary that there be one principle of nature or many. And each position has claimed the opinions of the philosophers. Some of them, indeed, held that there is one principle, others held that there are many. And of those who held that there is one principle, some held that it was immobile, as did Parmenides and Melissus, whose opinion he will examine below. Some, however, held that it was mobile, as did. the natural philosophers. Of these, some held that air was the principle of all natural things, as Diogenes; others that it was water, as Thales; others that it was fire, as Heraclitus; and still others some mean between air and water, such as vapour. But none of those who held that there was only one principle said that it was earth because of its density. For they held that principles of this sort were mobile, because they said that other things come to be through the rarefication and condensation of certain of these principles. Of those who held the principles to be many, some held them to be finite, others held that they were infinite. Of those who held that they were finite (although more than one) some held that there were two, i.e., fire and earth, as Parmenides will say below [L 10]. Others held that there were three, i.e., fire, air and water (for ‘they thought earth to be in some way composed because of its density). Others, however, held that there were four, as Empedocles did, or even some other number, because even Empedocles himself along with the four elements posited two other principles, namely, friendship and strife. Those who held that there was an infinite plurality of principles had a diversity of opinions. For Democritus held that indivisible bodies which are called atoms are the principles of all things. And he held that bodies of this sort were all of one genus according to nature, but that they differed according to figure and form, and that they not only differed but even had contrariety among themselves. For he held three contrarieties: one according to figure, which is between the curved and the straight, another according to order, which is the prior and the posterior, and another according to position, namely, before and behind, above and below, to the right and to the left. And so he held that from these bodies existing of one nature different things come to be according to the diversity of the figure, position and order of the atoms. In this opinion, then, he gives us some basis for understanding the opposing opinion, namely that of Anaxagoras who held that the principles were infinite, but not of one genus according to nature. For he held that the principles of nature were the infinite, smallest parts of flesh and bone and other such things, as will be made clear below. It must be noted, however, that he did not divide these many principles into mobile and immobile. For none of these who held that the first principles were many held that they were immobile. For since an place contrariety in the principles, and since it is natural for contraries to change, immobility could not stand with a plurality of principles.
lib. 1 l. 2 n. 3 Deinde cum dicit: similiter autem quaerunt etc., ostendit quod eadem diversitas opinionum est circa entia. Et dicit quod similiter physici, inquirentes de iis quae sunt, idest de entibus, quaerunt quot sint, utrum scilicet unum aut plura; et si sint multa, utrum sint finita vel infinita. Et ratio huius est, quia antiqui physici non cognoverunt nisi causam materialem, de aliis autem causis parum tetigerunt. Ponebant autem formas naturales esse accidentia, sicut et artificiales: sicut ergo tota substantia artificialium est eorum materia, ita sequebatur secundum eos quod tota substantia naturalium esset eorum materia. Unde qui ponebant tantum unum principium, puta aerem, putabant quod alia entia essent aer secundum suam substantiam: et simile est de aliis opinionibus. Et hoc est quod dicit, quod physici quaerunt ex quibus sunt quae sunt: idest, inquirendo de principiis inquirunt causas materiales, ex quibus entia esse dicuntur. Unde patet quod quando inquirunt de entibus, utrum sint unum aut plura, eorum inquisitio est de principiis materialibus, quae elementa dicuntur.	14. Secondly, at the point where he says, ‘A similar inquiry is made...’ (184 b 23; L9), he shows that there is the same diversity of opinions concerning beings. He says that in like manner the physicists, when inquiring about those things which are, i.e., about beings, wondered how many there are, i.e., whether there is one or many; and if many, whether finite or infinite. And the reason for this is that the ancient physicists did not know any cause but the material cause (although they touched lightly upon the other causes). Rather they held that the natural forms were accidents, as the forms of artificial things are. Since, therefore, the whole substance of artificial things is their matter, so it followed, according to them, that the whole substance of natural things would be their matter. Hence those who held one principle only, for example, air, thought that other beings were air according to their substance. And the same is true of the other opinions. Hence Aristotle says that the physicists seek what is in that from which things are, i.e., in inquiring about principles they sought the material causes from which beings are said to be. Whence it is clear that when they inquire about beings, whether they are one or many, their inquiry concerns the material principles which are called elements.
lib. 1 l. 2 n. 4 Deinde cum dicit: id quidem igitur etc., ostendit quod aliquam istarum opinionum improbare non pertinet ad naturalem. Et circa hoc duo facit: primo ostendit quod improbare opinionem Parmenidis et Melissi non pertinet ad scientiam naturalem; secundo assignat rationem quare ad praesens est utile eam improbare, ibi: sed quoniam de natura et cetera. Circa primum duo facit: primo ostendit quod non pertinet ad scientiam naturalem improbare praedictam opinionem; secundo quod non pertinet ad eam solvere rationes quae ad probandum ipsam inducuntur, ibi: aut solvere rationem et cetera. Primum ostendit duabus rationibus, quarum secunda incipit ibi: simile igitur et cetera. Dicit ergo primo quod non pertinet ad scientiam naturalem intendere ad perscrutandum de hac opinione, si ens est unum et immobile. Iam enim ostensum est quod non differt secundum intentionem antiquorum philosophorum, ponere unum principium immobile, et ponere unum ens immobile. Et quod improbare hanc opinionem ad naturalem non pertineat, sic ostendit. Ad geometriam non pertinet inducere rationem contra destruentem sua principia; sed hoc vel pertinet ad aliquam aliam scientiam particularem (si tamen geometria sit subalternata alicui particulari scientiae; sicut musica arithmeticae subalternatur, ad quam pertinet disputare contra negantem principia musicae); vel hoc pertinet ad scientiam communem, scilicet ad logicam vel metaphysicam. Sed praedicta positio destruit principia naturae; quia si sit solum unum ens, et sic unum, scilicet immobile, ut sic ex eo fieri alia non possint, tolletur ratio principii; quia omne principium aut est principium alicuius aut aliquorum. Ad positionem igitur principii sequitur multitudo, quia aliud est principium et aliud id cuius est principium; qui igitur negat multitudinem, tollit principia: non igitur debet contra hanc positionem disputare naturalis.	15. Next where he says, ‘Now to investigate ...’ (184 b 25), he shows that it does not pertain to natural science to disprove some of these opinions. And concerning this he makes two points. First he shows that it does not pertain to natural science to disprove the opinion of Parmenides and Melissus. Secondly, where he says, ‘At the same time the holders of the theory...’ (185 a 18),2 he gives a reason why it is useful to the present work to disprove this opinion. Concerning the first part he makes two points. First he shows that it does not pertain to natural science to disprove the aforesaid opinion. Secondly, where he says, ‘... or like refuting ...’ (185 a 8 #17), he shows that it does not pertain to natural science to resolve the arguments which are brought forth to prove this opinion. He establishes his first point with two arguments, the second , of which begins where he says, ‘To inquire therefore ...’ (185 a 5 #16). He says, therefore, that it does not pertain to natural science to undertake a thorough consideration of the opinion whether being is one and immobile. For it has already been shown that there is no difference, according to the intention of the ancient philosophers, whether we hold one immobile principle or one immobile being. And that it should not pertain to natural science to disprove this opinion he shows as follows. It does not pertain to geometry to bring forth reasons against an argument which destroys its principles. Rather, this either pertains to some other particular science (if, indeed, geometry is subalternated to some particular science, such as music is subalternated to arithmetic, to which it pertains to dispute against any position denying the principles of music), or it pertains to a common science such as logic or metaphysics. But the aforesaid position destroys the principles of nature. For if there is only one being, and if this being is immobile, such that from it others cannot come to be, then the very nature of a principle is taken away. For every principle is either a principle of some thing or of some things. Therefore, if we posit a principle, a multiplicity follows, because one is the principle and the other is that of which it is the principle. Whoever, therefore, denies multiplicity removes principles. Therefore natural science ought not to argue against this position.
lib. 1 l. 2 n. 5 Deinde cum dicit: simile igitur etc., ostendit idem alia ratione. Non enim requiritur ab aliqua scientia ut inducat rationem contra opiniones manifeste falsas et improbabiles; nam quolibet proferente contraria opinionibus sapientis solicitum esse, stultum est, ut dicitur I Topic. Hoc est ergo quod dicit, quod intendere ad perquirendum si ens est sic unum, scilicet immobile, simile est ac si disputaretur contra quamlibet aliam positionem improbabilem, ut puta contra positionem Heracliti, qui dixit omnia semper moveri et nihil esse verum; vel contra positionem alicuius qui diceret quod totum ens est unus homo, quae quidem positio esset omnino improbabilis. Et tamen qui ponit esse ens unum tantum immobile, cogitur ponere totum ens esse aliquod unum. Sic igitur patet quod non est naturalis scientiae contra hanc positionem disputare.	16. Next where he says, ‘To inquire therefore...’(185 a 5), he shows the same point with another argument. It is not required of any science that it bring forth arguments against manifestly false and improbable opinions. For to worry about one who offers positions contrary to the opinions of the wise is stupid, as is said in Topics, I:11. He says, therefore, that to undertake a thorough consideration of the question whether being is one, and hence immobile, is like arguing against any other improbable position. For example, it is like arguing against the position of Heraclitus, who said that all things are always moved and that nothing is true; or against the position of one who would say that the whole of being is one man, which position, indeed, would be altogether improbable. And indeed whoever holds being to be only one immobile thing is forced to hold that the whole of being is some one thing. It is clear, therefore, that it does not belong to natural science to argue against this position.
lib. 1 l. 2 n. 6 Deinde cum dicit: aut solvere etc., ostendit quod non est naturalis etiam solvere praedictorum philosophorum rationes. Et hoc per duas rationes, quarum secunda ponitur ibi: nobis autem subiiciantur et cetera. Probat ergo primo propositum per hoc quod non exigitur in aliqua scientia ut solvantur rationes sophisticae, quae manifestum defectum habent vel formae vel materiae. Et hoc est quod dicit, quod simile est intendere ad improbabiles rationes aut etiam solvere rationem litigiosam, idest sophisticam. Hoc autem quod sint sophisticae, habent utraeque rationes et Melissi et Parmenidis: peccant enim in materia, unde dicit quod falsa recipiunt, idest falsas propositiones assumunt; et peccant in forma, unde dicit quod non syllogizantes sunt. Sed ratio Melissi est magis onerosa, idest vana et fatua, et non habens defectum, idest non inducens dubitationem: et hoc infra ostendetur. Non est autem inconveniens si uno inconvenienti dato alia sequantur. Sic igitur concludi potest quod non requiritur a philosopho naturali quod solvat huius rationes.	17. Next when he says, ‘... or like refuting ...’ (185 a 8), he shows that it does not belong to natural science even to resolve the arguments of the aforementioned philosophers. And this for two reasons, the second of which begins where he says, ‘We physicists ...’ (185 a 13 #18). First he proves his position by pointing out that it is not incumbent upon any science to resolve sophistic arguments which have an obvious defect of form or matter. He says that to deal with improbable arguments is like solving a contentious or sophistic argument. But each argument of both Melissus and Parmenides is sophistic, for they err in matter, whence he says that they have accepted what is false, i.e., they assume false propositions, and they err in form, whence he says that they are not syllogizing. But the position of Melissus is much worse, i.e., more vain and foolish and does not cause any difficulty. This will be shown below [L 5]. Moreover, it is not inconsistent that given one inconsistency another should follow. Therefore it can be concluded that it is not required of the philosopher of nature that he resolve the arguments of this man.
lib. 1 l. 2 n. 7 Deinde cum dicit: nobis autem subiiciantur etc., ponit secundam rationem ad idem: quae talis est. In scientia naturali supponitur quod naturalia moveantur vel omnia vel quaedam: quod dicit quia de quibusdam est dubium si moventur et qualiter moventur, puta de anima, de centro terrae, de polo caeli, et formis naturalibus, et aliis huiusmodi. Et quod naturalia moveantur, potest manifestum esse ex inductione; quia ad sensum apparet quod res naturales moventur. Est autem necessarium motum supponi in scientia naturali, sicut necessarium est supponi naturam, in cuius definitione ponitur motus; est enim natura principium motus, ut infra dicetur. Hoc autem habito, quod motus supponatur in scientia naturali, ulterius procedit ad propositum ostendendum per hoc quod non omnes rationes sunt solvendae in aliqua scientia, sed solum illae quae concludunt aliquod falsum ex principiis illius scientiae: quaecumque vero non concludunt ex principiis scientiae, sed ex contrariis principiorum, non solvuntur in illa scientia. Et hoc probat per exemplum in geometricis dicens: ut tetragonismum, idest quadraturam circuli, hunc quidem qui est per decisiones circumferentiae, dissolvere pertinet ad geometram, quia nihil supponit contrarium principiis scientiae. Voluit enim quidam invenire quadratum aequale circulo dividendo circumferentiam circuli in multas partes, et singulis partibus supponendo lineas rectas: et sic, inveniendo aliquam figuram sicut rectilineam aequalem alicui illarum figurarum quae continentur a decisione circumferentiae et corda, aut pluribus aut omnibus, aestimabat se invenisse figuram rectilineam aequalem toti circulo, cui facile erat invenire quadratum aequale per principia geometriae: et sic putabat se invenire posse quadratum aequale circulo. Sed non sufficienter argumentabatur: quia licet illae decisiones consumerent totam circumferentiam circuli, non tamen figurae contentae a decisione circumferentiae et lineis rectis, comprehendebant totam superficiem circularem. Sed dissolvere quadraturam Antiphontis, non pertinet ad geometram, quia utebatur contrariis principiorum geometriae. Describebat enim in circulo aliquam figuram rectilineam, puta quadratum, et dividebat arcus quibus subtendebantur latera quadrati, singulos in duo media, et a punctis decisionum ducebat lineam rectam ad omnes angulos quadrati; et sic resultabat in circulo figura octo angulorum, quae plus accedebat ad aequalitatem circuli quam quadratum. Iterum dividebat arcus quibus subtendebantur latera figurae octo angulorum, singulos in duo media; et sic ducendo lineas rectas a punctis decisionum ad angulos praedictae figurae, resultabat figura sedecim angulorum, quae adhuc plus accedebat ad aequalitatem circuli. Semper ergo dividendo arcus, et ducendo lineas rectas ad angulos figurae praeexistentis, consurgit figura propinquius se habens ad aequalitatem circuli. Dicebat autem quod non est procedere in infinitum in decisione arcuum: erit ergo devenire ad aliquam figuram rectilineam aequalem circulo, cui poterit quadratum aequari. Quia igitur supponebat quod arcus non semper dividuntur in duo media, quod est contrarium principiis geometriae, huiusmodi rationem dissolvere non pertinet ad geometram. Quia igitur rationes Parmenidis et Melissi supponunt ens esse immobile, ut infra patebit; hoc autem est contra principia supposita in scientia naturali; sequitur quod solvere huiusmodi rationes, non pertinet ad philosophum naturalem.	18. He sets forth the second argument for this where he says, ‘We physicists...’ (185 a 13). The argument is as follows. In natural science it is supposed that natural things are moved, either all or some of them. He says this because there is doubt whether some things are moved and how they are moved, for example, about the soul and the centre of the earth, and the pole of heaven, and about natural forms and other such things. But the fact that natural things are moved can be made clear from induction, for it is apparent to the sense that natural things are moved. It is as necessary that motion be supposed in natural science as it is necessary that nature be supposed. For motion is placed in the definition of nature, for nature is a principle of motion, as will be said below [II, L1]. Having established this point, that motion is supposed in natural science, he proceeds further to prove his position as follows. Not A arguments must be resolved in any science, but only those which conclude to something false from the principles of that science. Any arguments which do not reach their conclusions from the principles of the science, but from the contraries of these principles, are not resolved in that science. He proves this by an example taken from geometry saying that it pertains to geometry to resolve the problem of squaring, i.e., the squaring of a circle by dissecting the circumference, because this method supposes nothing contrary to the principles of the science of geometry. For somebody wished to find a square equal to a circle by dividing the circumference of the circle into many parts and placing straight lines in each part. And so by finding some figure, which was rectilinear, equal to some of the figures which were contained by the dissections of the circumference and the cords (either many or all), he thought he had found a rectilinear figure equal to the whole circle, to which it was easy to find an equal square through the principles of geometry. And thus he thought that he was able to find a square equal to a circle. But he did not argue well enough, for although these dissections used up the whole circumference of the circle, the figures contained by the dissections of the circumference and the straight lines did not encompass the whole circular surface. But to resolve the square of Antiphon does not pertain to geometry, because he used principles contrary to those of geometry. For he described in a circle a certain rectilinear figure, for example, a square. And he divided in half the arcs by which the sides of the square were subtended. And from the points of dissection he led straight lines to all the angles of the square. And then there resulted in the circle a figure of eight angles, which more closely approached equality with the circle than the square. Then he again divided in half the arcs by which the sides of the octagon were subtended, and thus by leading straight lines from the points of dissection to the angles of this figure there resulted a figure of sixteen angles, which still further approached equality with the circle. Therefore, by always dividing the arcs and leading straight lines to the angles of the figure already existing there will arise a figure very near to equality with the circle. He said, then, that it was impossible to proceed to infinity in the dissection of arcs. Therefore, it was necessary to arrive at some rectilinear figure equal to the circle to which some square could be equal. But, because he supposed that an arc is not always divisible in half, which is contrary to the principles of geometry, it does not pertain to geometry to resolve an argument of this sort. Therefore, because the arguments of Parmenides and Melissus suppose being to be immobile (as will be shown below [L5]), and since this is contrary to the principles supposed in natural science, it follows that it does not pertain to the natural philosopher to resolve arguments of this sort.
lib. 1 l. 2 n. 8 Deinde cum dicit: sed quoniam de natura etc., assignat rationem quare disputet contra praedictam positionem. Et dicit quod quia praedicti philosophi loquebantur de rebus naturalibus, licet non inducerent defectus, idest dubitationes naturales; utile est ad propositum disputare de huiusmodi opinionibus: quia etsi non sit scientiae naturalis disputare contra huiusmodi positiones, pertinet tamen ad philosophiam primam.	19. Next where he says, ‘At the same time ...’ (185 a 18), he states why he will argue against the aforementioned position. He says that because the philosophers mentioned above did speak of natural things, even though they did not create a problem (that is, in the sphere of natural science), it is useful for his present purpose to argue against opinions of this sort. For even though it does not pertain to natural science to argue against such positions, it does pertain to first philosophy.