Ut quod prope sunt planetae, propter id quod non scintillant. Sit in quo C planetae, in quo B non scintillare, in quo A prope esse. Verum igitur est B de C dicere; planetae enim non scintillant. Sed et A de B, non scintillans enim prope esse; hoc autem accipitur per inductionem aut per sensum. Necesse est ergo A ipsi C inesse, quare demonstratum est quod erraticae prope sint. Hic igitur syllogismus non est ‘propter quid,’ sed ‘quia’; non enim ex eo quod non scintillant prope sunt, sed propter id quod prope sunt non scintillant. a30. Thus (2) (a) you might prove as follows that the planets are near because they do not twinkle: let C be the planets, B not twinkling, A proximity. Then B is predicable of C; for the planets do not twinkle. But A is also predicable of B, since that which does not twinkle is near — we must take this truth as having been reached by induction or sense-perception. Therefore, A is a necessary predicate of C; so that we have demonstrated that the planets are near. This syllogism, then, proves not the reasoned fact but only the fact; since they are not near because they do not twinkle, but, because they are near, do not twinkle. Contingit autem et per alterum alterum monstrare, et erit ‘propter quid’ demonstratio, ut sit C erraticae, in quo B prope esse, A non scintillare; est igitur et B in C, quare et in C A, et in B A, quod est non scintillare. Et erit ‘propter quid’ syllogismus; accepta est enim prima causa. a39. The major and middle of the proof, however, may be reversed, and then the demonstration will be of the reasoned fact. Thus: let C be the planets, B proximity, A not twinkling. Then B is an attribute of C, and A — not twinkling — of B. Consequently A is predicable of C, and the syllogism proves the reasoned fact, since its middle term is the proximate cause. Iterum sic lunam demonstrant, quod per incrementa circularis sit. Sic quidem igitur ipsius ‘quia’ factus est syllogismus, e converso autem posito medio ipsius ‘propter quid’ fit syllogismus; non enim propter augmenta circularis est, sed quia circularis est accipit augmenta huiusmodi. Luna sit in quo C, in quo B augmentum, in quo A circularis. b3. Another example is the inference that the moon is spherical from its manner of waxing. Thus: since that which so waxes is spherical, and since the moon so waxes, clearly the moon is spherical. Put in this form, the syllogism turns out to be proof of the fact, but if the middle and major be reversed it is proof of the reasoned fact; since the moon is not spherical because it waxes in a certain manner, but waxes in such a manner because it is spherical. (Let C be the moon, B spherical, and A waxing.) In quibus autem media non convertuntur et est notius quod non est causa, ‘quia’ demonstratur quidem, sed ‘propter quid’ non. b10. Again (b), in cases where the cause and the effect are not reciprocal and the effect is the better known, the fact is demonstrated but not the reasoned fact. 192. Sed ‘quia’ differt et ‘propter quid’ scire. Postquam Philosophus determinavit de demonstratione ‘propter quid,’ hic ostendit differentiam inter demonstrationem ‘quia’ et demonstrationem ‘propter quid.’ Knowledge of the fact. After determining about demonstration propter quid, the Philosopher here shows the difference between demonstration quia and demonstration propter quid. Et circa hoc duo facit: And he does two things about this. primo ostendit differentiam utriusque in eadem scientia; First, he shows how they differ in the same science. secundo in diversis; ibi: alio autem modo differt ‘propter quid,’ etc. Second, in diverse sciences, at: but there is another way (78b33; [207]). Circa primum duo facit: Concerning the first he does two things. primo ponit duplicem differentiam utriusque demonstrationis in eadem scientia; First, he states the twofold difference between the two in the same science. secundo manifestat per exempla, ibi: ut quod prope sunt planetae, etc. Second, he clarifies this with examples, at: thus you might prove (78a30; [196]). 193. Dicit ergo primo: superius dictum est quod demonstratio est syllogismus faciens scire et quod demonstratio ex causis rei procedit et primis et immediatis; quod intelligendum est de demonstratione ‘propter quid'. Sed tamen differt scire ‘quia’ ita est et ‘propter quid’ ita sit; et cum demonstratio sit syllogismus faciens scire, ut dictum est, oportet etiam quod demonstratio quae facit scire ‘quia’ differat a demonstratione quae facit scire ‘propter quid.’ Et horum quidem differentia primo consideranda est in eadem scientia; postea consideranda est in diversis scientiis. He says therefore first (78a22) that, as said above, demonstration is a syllogism causing scientific knowledge and proceeds from the causes both first and immediate of a thing. Now, this is to be understood as referring to demonstration 'propter quid'. But there is a difference between knowing 'that' a thing is so and 'why' it is so. Therefore, since demonstration is a syllogism causing scientific knowledge, as has been said, it is necessary that a demonstration 'quia' which makes one know that a thing is so should differ from the demonstration 'propter quid' which makes one know why. Consequently, this difference must be considered first in the same science and later in sciences that are diverse. 194. In una autem scientia dupliciter differt utrumque praedictorum, secundum duo quae requirebantur ad demonstrationem simpliciter, quae facit scire ‘propter quid,’ scilicet quod sit ex causis, et quod sit ex immediatis. —Uno igitur modo differt scire ‘quia’ ab hoc quod est scire ‘propter quid,’ quia scire ‘quia’ est si non fiat syllogismus demonstrativus per non medium, idest per immediatum, sed fiat per mediata: sic enim non accipietur prima causa, cum tamen scientia quae est ‘propter quid’ sit secundum primam causam; et ita non erit scientia ‘propter quid.’ In one and the same science each of the above is said to differ in regard to the two things required for demonstration in the strict sense—which causes knowledge of the why—namely, that it be from causes and from immediate causes. Hence one way that scientific knowledge 'quia' differ from 'propter quid' is that it is the former if the syllogism is not through, immediate principles but through mediate ones. For in that case the first cause will not be employed, whereas science propter quid is according to the first cause; consequently, the former will not be science 'propter quid'. 195. Alio modo differunt, quia scire ‘quia’ est quando fit syllogismus non quidem per media, idest per mediata, sed per immediata, sed non fit per causam, sed fit per convertentia, idest per effectus convertibiles et immediatos; et tamen talis demonstratio fit per notius, alias non faceret scire: non enim pervenimus ad cognitionem ignoti nisi per aliquid magis notum. Nihil enim prohibet duorum aeque praedicantium, idest convertibilium, quorum unus sit causa et aliud effectus, notius esse aliquando non causam, sed magis effectum; nam effectus aliquando est notior causa quo ad nos et secundum sensum, licet causa sit semper notior simpliciter et secundum naturam. Et ita per effectum notiorem causa potest fieri demonstratio non faciens scire ‘propter quid,’ sed tantum ‘quia.’ It differs in another way, because it is science 'quia' when the syllogism, although not through middles, that is, mediate, but through immediate things, is not through the cause but through “convertence,” that is, through effects convertible and immediate. Hence a demonstration of this kind is through the better known, namely, to us; otherwise it would not effect scientific knowledge. For we do not reach a knowledge of the unknown except through something better known. However in the case of two things equally predicable, that is, convertible, one of which is the cause and the other the effect, there is nothing to preclude that now and then the better known will not be the cause but the effect. For sometimes the effect is better known than the cause both in respect to us and according to sense-perception, although absolutely and according to nature the cause is the better known. Consequently, through an effect better known than the cause there can be demonstration which does not engender 'propter quid' knowledge but only 'quia'. 196. Deinde cum dicit: ut quod prope sunt planetae, etc., manifestat praedictam differentiam per exempla. Then, at: thus you might prove (78a30) he clarifies these differences by examples. Et dividitur in partes duas: And this is divided into two parts. in prima ponit exempla de demonstratione ‘quia,’ quae est per effectum; In the first he develops an example of the demonstration 'quia' which is through an effect. in secunda de demonstratione ‘quia’ quae est per causam mediatam, ibi: amplius in quibus medium extra ponitur, etc. In the second of demonstration 'quia' which is through a mediate cause, at: this also occurs when the middle (78b13; [201]). Prima dividitur in duas: The first is divided into two parts. in prima ponit exempla de syllogismo qui fit per effectum convertibilem; In the first he gives an example of a syllogism which is through a convertible effect. in secunda de syllogismo qui fit per effectum non convertibilem, ibi: in quibus autem media, etc. In the second of a syllogism through a nonconvertible effect, at: again, in cases where the cause (78b10; [200]). Prima dividitur in duas secundum duo exempla quae ponit; secunda pars ibi: iterum sic lunam demonstrant, etc. The first is divided into two parts according to the two examples he gives, the second of which begins at: another example is the inference (78b3; [199]). Circa primum duo facit: Concerning the first he does two things. primo proponit exemplum de demonstratione ‘quia’ quae est per effectum; First, he gives an example of demonstration 'quia' which is through an effect. secundo docet quomodo posset converti in demonstrationem ‘propter quid,’ ibi: contingit autem et per alterum, etc. Second, he states when it can be converted into a demonstration 'propter quid', at: the major and middle of the proof (78a39; [198]). 197. Dicit ergo primo quod demonstratio ‘quia’ per effectum est si quis concludat quod planetae sunt prope propter hoc quod non scintillant: non enim ‘non scintillare’ est causa quod planetae sint prope, sed e converso: propter hoc enim non scintillant planetae quia sunt prope, stellae enim fixae scintillant quia visus in comprehensione earum caligat propter earum distantiam. Formetur ergo syllogismus sic: sit in quo C planetae, idest accipiatur ‘planetae’ quasi minor extremitas, in quo B sit non scintillare, idest ‘non scintillare’ accipiatur medius terminus, in quo A sit prope esse, idest ‘prope esse’ accipiatur ut maior extremitas. Vera igitur est haec propositio: "Omne C est B", quia planetae non scintillant; et iterum verum est quod omne B est A, quia omnis stella non scintillans prope est; huius autem propositionis veritas oportet quod accipiatur per inductionem aut per sensum, quia effectus hic est notior causa quantum ad sensum; et sic sequitur conclusio quod omne C sit A, et sic demonstratum est quod planetae sive stellae erraticae prope sint. Hic igitur syllogismus non est ‘propter quid,’ sed est ‘quia’: non enim propter hoc quod non scintillant planetae sunt prope, sed propter id quod prope sunt, non scintillant. He says therefore first (78a30) that demonstration 'quia' is through an effect if one concludes for example that the planets are near because they do not twinkle. For 'non-twinkling' is not the cause why the planets are near, but vice versa: for the planets do not twinkle because they are near. For the fixed stars twinkle because in gazing at them the sight is beclouded on account of the distance. Therefore, the syllogism might be formed in the following way: “Whatever does not twinkle is near; but the planets do not twinkle: therefore, they are near.” Here we let C be the planets, that is, let 'planets' be the minor extreme, and let B consist in not twinkling, and A “to be near” be the major extreme. Then the proposition, “Every C is B,” is true, namely, the planets do not twinkle. Also it is true that “Every B is A,” that is, every star that does not twinkle is near. Rowever, the truth of such a proposition must be obtained through induction or through sense perception, because the effect here is better known than the cause. And so, the conclusion, “Every C is A,” follows. In this way, then, it has been demonstrated that the planets, that is, the wandering stars, are near. Consequently, this syllogism is not “propter quid” but “quia.“ For it is not because they do not twinkle that planets are near but rather, because they are near, they do not twinkle. 198. Deinde cum dicit: contingit autem et per alterum, etc., docet quomodo demonstratio ‘quia’ convertatur in demonstrationem ‘propter quid,’ dicens quod contingit et per alterum demonstrare alterum, idest per hoc quod est prope esse demonstrare quod non scintillant, et sic erit demonstratio ‘propter quid’; ut sit C erraticae, idest accipiatur ‘stella erratica’ minor extremitas; in quo B sit prope <esse>;, idest ‘prope esse’ accipiatur ut medius terminus, quod supra erat maior extremitas; A sit non scintillare, idest accipiatur ‘non scintillare’ maior extremitas, quod supra erat medius terminus; est igitur et B in C, quia omnis planeta prope est, et A est in B, quia omnis planeta, quae prope est, non scintillat; quare sequitur quod et A sit in C, scilicet, quod omnis planeta non scintillet. Et sic erit syllogismus ‘propter quid’, cum accepta sit prima et immediata causa. Then, at: the major and middle of the proof (78a39) he teaches how a demonstration 'quia' is changed to a demonstration 'propter quid'. And he says that it is possible to demonstrate the one through the other, that is, to demonstrate that they do not twinkle, because they are near. Then the demonstration will be 'propter quid'. Thus let C be the wanderers, that is, let 'wandering star' be the minor extreme; let B consist in being near, that is, let 'to be near', which was the major extreme above, be the middle term; and let A consist in not twinkling, that is, let 'not to twinkle', which above was the middle term, now be the major term. Therefore, B is in C, that is, “Every planet is near”; and A is in B, that is, “Any planet which is near does not twinkle.” Wherefore, it follows that A is in C, that is, “A planet does not twinkle.” In this way we have a syllogism 'propter quid', since it rests on the first and immediate cause. 199. Deinde cum dicit: iterum sic lunam demonstrant, etc., ponit aliud exemplum ad idem, dicens quod sic, idest demonstratione faciente scire ‘quia,’ demonstrant quod luna sit circularis per incrementa, quibus scilicet omni mense augetur et minuitur, sic argumentantes: "Omne quod sic augetur quasi arcualiter, circulare est; augetur autem sic luna; ergo est circularis". Sic igitur factus est syllogismus demonstrans ‘quia', sed, e converso posito medio, ipsius fit syllogismus ‘propter quid’, scilicet si ponatur ‘circulare’ ut medius terminus et ‘augmentum’ ut maior extremitas: non enim ideo circularis est luna quia sic augetur, sed, quia circularis est, ideo talia augmenta recipit. Sit ergo luna in quo C, idest minor extremitas; augmentum in quo B, idest medius terminus, circularis in quo A, idest maior extremitas. Et hoc intelligendum est in syllogismo ‘quia’; e converso autem in syllogismo ‘propter quid.’ Then, at: another example is the inference (78b3) he presents another example of this, saying that in this way (that is, by means of a demonstration 'quia'), one demonstrates that the moon is round because of its phases, according to which it waxes and wanes every month. They argue thus: “Everything which waxes thus circularly is circular; but the moon waxes thus: therefore, it is circular.” Put in this form it is a syllogism demonstrating 'quia'. But if the middle be interchanged, that is, if 'circular' be made the middle term and 'waxes' the major term, “it becomes a demonstration 'propter quid'. For the moon is not circular because it waxes in that way, but because it is circular it undergoes such phases. Therefore, let C be the moon, that is, the minor extreme; let waxing be B, that is, the major extreme, and let circular be B, the middle term. This will be the situation in the syllogism propter quid. 200. Deinde cum dicit: in quibus autem media, etc., ostendit quod sit demonstratio ‘quia’ per effectum non convertibilem, dicens quod in illis etiam syllogismis in quibus media non convertuntur cum extremis, et accipitur ut notius quo ad nos scilicet loco medii quod non est causa, sed magis effectus, demonstratur quidem ‘quia,’ sed non ‘propter quid’. Then, at: again, in cases where the cause (78b10) he shows that a demonstration through a non-convertible effect is quid. He says, therefore, that even in those syllogisms in which the middles are not converted with the extremes, and in which an effect rather than a cause is taken as the middle better known in reference to us, even in those cases the demonstration is “quia” and not “propter quid." Et quidem si tale medium convertatur cum maiori extremitate et excedat minorem, manifestum est quod conveniens fit syllogismus, sicut si probetur de Venere quod sit prope quia non scintillat. Si autem e converso minor terminus esset in plus quam medium assumptum, non esset conveniens syllogismus: non enim potest de stella universaliter concludi quod sit prope per hoc quod non scintillet. In comparatione autem ad maiorem terminum est e converso: nam, si medium sit in minus quam maior terminus, conveniens fit syllogismus, sicut si per hoc quod est moveri motu progressivo probetur de aliquo quod habeat animam sensibilem. Si autem sit in plus, non fit conveniens syllogismus: nam ab effectu qui a pluribus causis procedere potest, non potest una illarum concludi, sicut non potest concludi quod aliquis habeat febrem ex citatione pulsus. If the middle be such that it can be converted with the major extreme and it exceeds the minor, then obviously it is a fitting syllogism; for example, if one proves that Venus is near because it does not twinkle. On the other hand, if the minor exceeded the middle, it would not be a fitting syllogism: for one cannot conclude universally of stars that they are near because they do not twinkle. Quite the contrary is true in comparison to the major term: for if the middle is in less things than is the major term, the syllogism is fitting, as when it is proved that someone has a sensible soul on the ground that he is capable of progressive local motion. But if it is in more, than the syllogism is not fitting, for from an effect which can proceed from several causes, one of them cannot be concluded. Thus, one cannot conclude from a rapid pulse that he has a fever. Lectio 24 Lecture 24 De demonstratione quia per non immediata How there is demonstration quia through things not immediately connected Amplius in quibus medium extra ponitur: et in his enim ipsius ‘quia,’ non ‘propter quid’ demonstratio est, non enim dicitur causa. b13. This also occurs (1) when the middle falls outside the major and minor, for here too the strict cause is not given, and so the demonstration is of the fact, not of the reasoned fact. Ut quare non respirat paries? Quia non est animal. Si enim haec non respirandi causa est, oportet animal esse causam respirandi, ut si negatio causa est ipsius non esse, affirmatio est esse, sicut sine mensura esse calida et frigida non sanandi causa est, cum mensura esse est sanandi causa. Similiter autem est si affirmatio ipsius esse, et negatio non esse. In his autem sic demonstratis non contingit quod dictum est; non enim omne respirat animal. b14. For example, the question ‘Why does not a wall breathe?’ might be answered, ‘Because it is not an animal’; but that answer would not give the strict cause, because if not being an animal causes the absence of respiration, then being an animal should be the cause of respiration, according to the rule that if the negation of causes the non-inherence of y, the affirmation of x causes the inherence of y; e.g., if the disproportion of the hot and cold elements is the cause of ill health, their proportion is the cause of health; and conversely, if the assertion of x causes the inherence of y, the negation of x must cause y’s non-inherence. But in the case given this consequence does not result; for not every animal breathes. Syllogismus autem huiusmodi causae fit in media figura. Ut sit A animal, in quo B respirare, in quo C paries; in B quidem igitur omni est A (omne enim respirans animal est), in C autem nullo, quare neque B in C nullo est; non igitur respirat paries. b24. A syllogism with this kind of cause takes place in the second figure. Thus: let A be animal, B respiration, C wall. Then A is predicable of all B (for all that breathes is animal), but of no C; and consequently B is predicable of no C; that is, the wall does not breathe. Comparantur autem huiusmodi causarum secundum excellentiam dictis; hoc autem est plurimum distans medium dicere, sicut est illud quod Anacharsis quod in Scythis non sunt sibilatores, neque enim vites. b27. Such causes are like far-fetched explanations, which precisely consist in making the cause too remote, as in Anacharsis’ account of why the Scythians have no flute-players; namely because they have no vines.