Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that habit is not a distinct species of quality. Because, as we have said (Article 1), habit, in so far as it is a quality, is "a disposition whereby that which is disposed is disposed well or ill." But this happens in regard to any quality: for a thing happens to be well or ill disposed in regard also to shape, and in like manner, in regard to heat and cold, and in regard to all such things. Therefore habit is not a distinct species of quality.

Objection 2: Further, the Philosopher says in the Book of the Predicaments (Categor. vi), that heat and cold are dispositions or habits, just as sickness and health. Therefore habit or disposition is not distinct from the other species of quality.

Objection 3: Further, "difficult to change" is not a difference belonging to the predicament of quality, but rather to movement or passion. Now, no genus should be contracted to a species by a difference of another genus; but "differences should be proper to a genus," as the Philosopher says in Metaph. vii, text. 42. Therefore, since habit is "a quality difficult to change," it seems not to be a distinct species of quality.

On the contrary, The Philosopher says in the Book of the Predicaments (Categor. vi) that "one species of quality is habit and disposition."

I answer that, The Philosopher in the Book of Predicaments (Categor. vi) reckons disposition and habit as the first species of quality. Now Simplicius, in his Commentary on the Predicaments, explains the difference of these species as follows. He says "that some qualities are natural, and are in their subject in virtue of its nature, and are always there: but some are adventitious, being caused from without, and these can be lost. Now the latter," i.e. those which are adventitious, "are habits and dispositions, differing in the point of being easily or difficultly lost. As to natural qualities, some regard a thing in the point of its being in a state of potentiality; and thus we have the second species of quality: while others regard a thing which is in act; and this either deeply rooted therein or only on its surface. If deeply rooted, we have the third species of quality: if on the surface, we have the fourth species of quality, as shape, and form which is the shape of an animated being." But this distinction of the species of quality seems unsuitable. For there are many shapes, and passion-like qualities, which are not natural but adventitious: and there are also many dispositions which are not adventitious but natural, as health, beauty, and the like. Moreover, it does not suit the order of the species, since that which is the more natural is always first.

Therefore we must explain otherwise the distinction of dispositions and habits from other qualities. For quality, properly speaking, implies a certain mode of substance. Now mode, as Augustine says (Gen. ad lit. iv, 3), "is that which a measure determines": wherefore it implies a certain determination according to a certain measure. Therefore, just as that in accordance with which the material potentiality is determined to its substantial being, is called quality, which is a difference affecting the substance, so that, in accordance with the potentiality of the subject is determined to its accidental being, is called an accidental quality, which is also a kind of difference, as is clear from the Philosopher (Metaph. v, text. 19).

Now the mode of determination of the subject to accidental being may be taken in regard to the very nature of the subject, or in regard to action, and passion resulting from its natural principles, which are matter and form; or again in regard to quantity. If we take the mode or determination of the subject in regard to quantity, we shall then have the fourth species of quality. And because quantity, considered in itself, is devoid of movement, and does not imply the notion of good or evil, so it does not concern the fourth species of quality whether a thing be well or ill disposed, nor quickly or slowly transitory.

But the mode of determination of the subject, in regard to action or passion, is considered in the second and third species of quality. And therefore in both, we take into account whether a thing be done with ease or difficulty; whether it be transitory or lasting. But in them, we do not consider anything pertaining to the notion of good or evil: because movements and passions have not the aspect of an end, whereas good and evil are said in respect of an end.

On the other hand, the mode or determination of the subject, in regard to the nature of the thing, belongs to the first species of quality, which is habit and disposition: for the Philosopher says (Phys. vii, text. 17), when speaking of habits of the soul and of the body, that they are "dispositions of the perfect to the best; and by perfect I mean that which is disposed in accordance with its nature." And since the form itself and the nature of a thing is the end and the cause why a thing is made (Phys. ii, text. 25), therefore in the first species we consider both evil and good, and also changeableness, whether easy or difficult; inasmuch as a certain nature is the end of generation and movement. And so the Philosopher (Metaph. v, text. 25) defines habit, a "disposition whereby someone is disposed, well or ill"; and in Ethic. ii, 4, he says that by "habits we are directed well or ill in reference to the passions." For when the mode is suitable to the thing's nature, it has the aspect of good: and when it is unsuitable, it has the aspect of evil. And since nature is the first object of consideration in anything, for this reason habit is reckoned as the first species of quality.

Reply to Objection 1: Disposition implies a certain order, as stated above (Article 1, ad 3). Wherefore a man is not said to be disposed by some quality except in relation to something else. And if we add "well or ill," which belongs to the essential notion of habit, we must consider the quality's relation to the nature, which is the end. So in regard to shape, or heat, or cold, a man is not said to be well or ill disposed, except by reason of a relation to the nature of a thing, with regard to its suitability or unsuitability. Consequently even shapes and passion-like qualities, in so far as they are considered to be suitable or unsuitable to the nature of a thing, belong to habits or dispositions: for shape and color, according to their suitability to the nature of thing, concern beauty; while heat and cold, according to their suitability to the nature of a thing, concern health. And in this way heat and cold are put, by the Philosopher, in the first species of quality.

Wherefore it is clear how to answer the second objection: though some give another solution, as Simplicius says in his Commentary on the Predicaments.

Reply to Objection 3: This difference, "difficult to change," does not distinguish habit from the other species of quality, but from disposition. Now disposition may be taken in two ways; in one way, as the genus of habit, for disposition is included in the definition of habit (Metaph. v, text. 25): in another way, according as it is divided against habit. Again, disposition, properly so called, can be divided against habit in two ways: first, as perfect and imperfect within the same species; and thus we call it a disposition, retaining the name of the genus, when it is had imperfectly, so as to be easily lost: whereas we call it a habit, when it is had perfectly, so as not to be lost easily. And thus a disposition becomes a habit, just as a boy becomes a man. Secondly, they may be distinguished as diverse species of the one subaltern genus: so that we call dispositions, those qualities of the first species, which by reason of their very nature are easily lost, because they have changeable causes; e.g. sickness and health: whereas we call habits those qualities which, by reason of their very nature, are not easily changed, in that they have unchangeable causes, e.g. sciences and virtues. And in this sense, disposition does not become habit. The latter explanation seems more in keeping with the intention of Aristotle: for in order to confirm this distinction he adduces the common mode of speaking, according to which, when a quality is, by reason of its nature, easily changeable, and, through some accident, becomes difficultly changeable, then it is called a habit: while the contrary happens in regard to qualities, by reason of their nature, difficultly changeable: for supposing a man to have a science imperfectly, so as to be liable to lose it easily, we say that he is disposed to that science, rather than that he has the science. From this it is clear that the word "habit" implies a certain lastingness: while the word "disposition" does not.

Nor does it matter that thus to be easy and difficult to change are specific differences (of a quality), although they belong to passion and movement, and not the genus of quality. For these differences, though apparently accidental to quality, nevertheless designate differences which are proper and essential to quality. In the same way, in the genus of substance we often take accidental instead of substantial differences, in so far as by the former, essential principles are designated.

Articulus 2

Argumentum 1

Ad secundum sic proceditur. Videtur quod habitus non sit determinata species qualitatis.

Quia, ut dictum est, habitus, secundum quod est qualitas, dicitur dispositio secundum quam bene aut male disponitur dispositum.

Sed hoc contingit secundum quamlibet qualitatem, nam et secundum figuram contingit aliquid bene vel male esse dispositum, et similiter secundum calorem et frigus, et secundum omnia huiusmodi.

Ergo habitus non est determinata species qualitatis.

Argumentum 2

Praeterea, philosophus, in praedicamentis, caliditatem et frigiditatem dicit esse dispositiones vel habitus, sicut aegritudinem et sanitatem. Sed calor et frigus sunt in tertia specie qualitatis. Ergo habitus vel dispositio non distinguuntur ab aliis speciebus qualitatis.

Argumentum 3

Praeterea, difficile mobile non est differentia pertinens ad genus qualitatis, sed magis pertinet ad motum vel passionem.

Nullum autem genus determinatur ad speciem per differentiam alterius generis; sed oportet differentias per se advenire generi, ut philosophus dicit, in VII metaphys..

Ergo, cum habitus dicatur esse qualitas difficile mobilis, videtur quod non sit determinata species qualitatis.

Sed Contra

Sed contra est quod philosophus dicit, in praedicamentis, quod una species qualitatis est habitus et dispositio.

Corpus

Respondeo dicendum quod philosophus, in praedicamentis, ponit inter quatuor species qualitatis primam, dispositionem et habitum. Quarum quidem specierum differentias sic assignat simplicius, in commento praedicamentorum, dicens quod qualitatum quaedam sunt naturales, quae secundum naturam insunt, et semper, quaedam autem sunt adventitiae, quae ab extrinseco efficiuntur, et possunt amitti. Et haec quidem, quae sunt adventitiae, sunt habitus et dispositiones, secundum facile et difficile amissibile differentes. Naturalium autem qualitatum quaedam sunt secundum id quod aliquid est in potentia, et sic est secunda species qualitatis.

Quaedam vero secundum quod aliquid est in actu, et hoc vel in profundum, vel secundum superficiem. Si in profundum quidem, sic est tertia species qualitatis, secundum vero superficiem, est quarta species qualitatis, sicut figura et forma, quae est figura animati.

Sed ista distinctio specierum qualitatis inconveniens videtur.

Sunt enim multae figurae et qualitates passibiles non naturales, sed adventitiae, et multae dispositiones non adventitiae, sed naturales, sicut sanitas et pulchritudo et huiusmodi.

Et praeterea hoc non convenit ordini specierum, semper enim quod naturalius est, prius est.

Et ideo aliter accipienda est distinctio dispositionum et habituum ab aliis qualitatibus. Proprie enim qualitas importat quendam modum substantiae. Modus autem est, ut dicit Augustinus, super Gen. Ad litteram, quem mensura praefigit, unde importat quandam determinationem secundum aliquam mensuram. Et ideo sicut id secundum quod determinatur potentia materiae secundum esse substantiale dicitur qualitas quae est differentia substantiae; ita id secundum quod determinatur potentia subiecti secundum esse accidentale, dicitur qualitas accidentalis, quae est etiam quaedam differentia, ut patet per philosophum in V metaphys..

Modus autem sive determinatio subiecti secundum esse accidentale, potest accipi vel in ordine ad ipsam naturam subiecti; vel secundum actionem et passionem quae consequuntur principia naturae, quae sunt materia et forma; vel secundum quantitatem. Si autem accipiatur modus vel determinatio subiecti secundum quantitatem, sic est quarta species qualitatis. Et quia quantitas, secundum sui rationem, est sine motu, et sine ratione boni et mali; ideo ad quartam speciem qualitatis non pertinet quod aliquid sit bene vel male, cito vel tarde transiens. Modus autem sive determinatio subiecti secundum actionem et passionem, attenditur in secunda et tertia specie qualitatis. Et ideo in utraque consideratur quod aliquid facile vel difficile fiat, vel quod sit cito transiens aut diuturnum. Non autem consideratur in his aliquid pertinens ad rationem boni vel mali, quia motus et passiones non habent rationem finis, bonum autem et malum dicitur per respectum ad finem. Sed modus et determinatio subiecti in ordine ad naturam rei, pertinet ad primam speciem qualitatis, quae est habitus et dispositio, dicit enim philosophus, in VII physic., loquens de habitibus animae et corporis, quod sunt dispositiones quaedam perfecti ad optimum; dico autem perfecti, quod est dispositum secundum naturam. Et quia ipsa forma et natura rei est finis et cuius causa fit aliquid, ut dicitur in II physic.

Ideo in prima specie consideratur et bonum et malum; et etiam facile et difficile mobile, secundum quod aliqua natura est finis generationis et motus.

Unde in V metaphys. Philosophus definit habitum, quod est dispositio secundum quam aliquis disponitur bene vel male.

Et in II ethic. Dicit quod habitus sunt secundum quos ad passiones nos habemus bene vel male.

Quando enim est modus conveniens naturae rei, tunc habet rationem boni, quando autem non convenit, tunc habet rationem mali.

Et quia natura est id quod primum consideratur in re, ideo habitus ponitur prima species qualitatis.

Ad 1

Ad primum ergo dicendum quod dispositio ordinem quendam importat, ut dictum est.

Unde non dicitur aliquis disponi per qualitatem, nisi in ordine ad aliquid. Et si addatur bene vel male, quod pertinet ad rationem habitus, oportet quod attendatur ordo ad naturam, quae est finis. Unde secundum figuram, vel secundum calorem vel frigus, non dicitur aliquis disponi bene vel male, nisi secundum ordinem ad naturam rei, secundum quod est conveniens vel non conveniens. Unde et ipsae figurae et passibiles qualitates, secundum quod considerantur ut convenientes vel non convenientes naturae rei, pertinent ad habitus vel dispositiones, nam figura, prout convenit naturae rei, et color, pertinent ad pulchritudinem; calor autem et frigus, secundum quod conveniunt naturae rei, pertinent ad sanitatem. Et hoc modo caliditas et frigiditas ponuntur a philosopho in prima specie qualitatis.

Ad 2

Unde patet solutio ad secundum. Licet a quibusdam aliter solvatur, ut simplicius dicit, in commento praedicamentorum.

Ad 3

Ad tertium dicendum quod ista differentia, difficile mobile, non diversificat habitum ab aliis speciebus qualitatis, sed a dispositione. Dispositio autem dupliciter accipitur, uno modo, secundum quod est genus habitus, nam in V metaphys.

Dispositio ponitur in definitione habitus; alio modo, secundum quod est aliquid contra habitum divisum.

Et potest intelligi dispositio proprie dicta condividi contra habitum, dupliciter. Uno modo, sicut perfectum et imperfectum in eadem specie, ut scilicet dispositio dicatur, retinens nomen commune, quando imperfecte inest, ita quod de facile amittitur; habitus autem, quando perfecte inest, ut non de facili amittatur. Et sic dispositio fit habitus, sicut puer fit vir. Alio modo possunt distingui sicut diversae species unius generis subalterni, ut dicantur dispositiones illae qualitates primae speciei, quibus convenit secundum propriam rationem ut de facili amittantur, quia habent causas transmutabiles, ut aegritudo et sanitas; habitus vero dicuntur illae qualitates quae secundum suam rationem habent quod non de facili transmutentur, quia habent causas immobiles, sicut scientiae et virtutes.

Et secundum hoc dispositio non fit habitus.

Et hoc videtur magis consonum intentioni Aristotelis.

Unde ad huius distinctionis probationem inducit communem loquendi consuetudinem, secundum quam qualitates quae secundum rationem suam sunt facile mobiles, si ex aliquo accidenti difficile mobiles reddantur, habitus dicuntur, et e converso est de qualitatibus quae secundum suam rationem sunt difficile mobiles; nam si aliquis imperfecte habeat scientiam, ut de facili possit ipsam amittere, magis dicitur disponi ad scientiam quam scientiam habere. Ex quo patet quod nomen habitus diuturnitatem quandam importat; non autem nomen dispositionis.

Nec impeditur quin secundum hoc facile et difficile mobile sint specificae differentiae, propter hoc quod ista pertinent ad passionem et motum, et non ad genus qualitatis. Nam istae differentiae, quamvis per accidens videantur se habere ad qualitatem, designant tamen proprias et per se differentias qualitatum. Sicut etiam in genere substantiae frequenter accipiuntur differentiae accidentales loco substantialium, inquantum per eas designantur principia essentialia.