Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that likeness is not a cause of love. For the same thing is not the cause of contraries. But likeness is the cause of hatred; for it is written (Prov. 13:10) that "among the proud there are always contentions"; and the Philosopher says (Ethic. viii, 1) that "potters quarrel with one another." Therefore likeness is not a cause of love.

Objection 2: Further, Augustine says (Confess. iv, 14) that "a man loves in another that which he would not be himself: thus he loves an actor, but would not himself be an actor." But it would not be so, if likeness were the proper cause of love; for in that case a man would love in another, that which he possesses himself, or would like to possess. Therefore likeness is not a cause of love.

Objection 3: Further, everyone loves that which he needs, even if he have it not: thus a sick man loves health, and a poor man loves riches. But in so far as he needs them and lacks them, he is unlike them. Therefore not only likeness but also unlikeness is a cause of love.

Objection 4: Further, the Philosopher says (Rhet. ii, 4) that "we love those who bestow money and health on us; and also those who retain their friendship for the dead." But all are not such. Therefore likeness is not a cause of love.

On the contrary, It is written (Ecclus. 13:19): "Every beast loveth its like."

I answer that, Likeness, properly speaking, is a cause of love. But it must be observed that likeness between things is twofold. One kind of likeness arises from each thing having the same quality actually: for example, two things possessing the quality of whiteness are said to be alike. Another kind of likeness arises from one thing having potentially and by way of inclination, a quality which the other has actually: thus we may say that a heavy body existing outside its proper place is like another heavy body that exists in its proper place: or again, according as potentiality bears a resemblance to its act; since act is contained, in a manner, in the potentiality itself.

Accordingly the first kind of likeness causes love of friendship or well-being. For the very fact that two men are alike, having, as it were, one form, makes them to be, in a manner, one in that form: thus two men are one thing in the species of humanity, and two white men are one thing in whiteness. Hence the affections of one tend to the other, as being one with him; and he wishes good to him as to himself. But the second kind of likeness causes love of concupiscence, or friendship founded on usefulness or pleasure: because whatever is in potentiality, as such, has the desire for its act; and it takes pleasure in its realization, if it be a sentient and cognitive being.

Now it has been stated above (Question 26, Article 4), that in the love of concupiscence, the lover, properly speaking, loves himself, in willing the good that he desires. But a man loves himself more than another: because he is one with himself substantially, whereas with another he is one only in the likeness of some form. Consequently, if this other's likeness to him arising from the participation of a form, hinders him from gaining the good that he loves, he becomes hateful to him, not for being like him, but for hindering him from gaining his own good. This is why "potters quarrel among themselves," because they hinder one another's gain: and why "there are contentions among the proud," because they hinder one another in attaining the position they covet.

Hence the Reply to the First Objection is evident.

Reply to Objection 2: Even when a man loves in another what he loves not in himself, there is a certain likeness of proportion: because as the latter is to that which is loved in him, so is the former to that which he loves in himself: for instance, if a good singer love a good writer, we can see a likeness of proportion, inasmuch as each one has that which is becoming to him in respect of his art.

Reply to Objection 3: He that loves what he needs, bears a likeness to what he loves, as potentiality bears a likeness to its act, as stated above.

Reply to Objection 4: According to the same likeness of potentiality to its act, the illiberal man loves the man who is liberal, in so far as he expects from him something which he desires. The same applies to the man who is constant in his friendship as compared to one who is inconstant. For in either case friendship seems to be based on usefulness. We might also say that although not all men have these virtues in the complete habit, yet they have them according to certain seminal principles in the reason, in force of which principles the man who is not virtuous loves the virtuous man, as being in conformity with his own natural reason.

Articulus 3

Argumentum 1

Ad tertium sic proceditur. Videtur quod similitudo non sit causa amoris. Idem enim non est causa contrariorum.

Sed similitudo est causa odii, dicitur enim Prov. XIII, quod inter superbos semper sunt iurgia; et philosophus dicit, in VIII ethic., quod figuli corrixantur ad invicem.

Ergo similitudo non est causa amoris.

Argumentum 2

Praeterea, Augustinus dicit, in IV confess., quod aliquis amat in alio quod esse non vellet, sicut homo amat histrionem, qui non vellet esse histrio.

Hoc autem non contingeret, si similitudo esset propria causa amoris, sic enim homo amaret in altero quod ipse haberet, vel vellet habere. Ergo similitudo non est causa amoris.

Argumentum 3

Praeterea, quilibet homo amat id quo indiget, etiam si illud non habeat, sicut infirmus amat sanitatem, et pauper amat divitias.

Sed inquantum indiget et caret eis, habet dissimilitudinem ad ipsa. Ergo non solum similitudo, sed etiam dissimilitudo est causa amoris.

Argumentum 4

Praeterea, philosophus dicit, in II rhetoric., quod beneficos in pecunias et salutem amamus, et similiter eos qui circa mortuos servant amicitiam, omnes diligunt.

Non autem omnes sunt tales. Ergo similitudo non est causa amoris.

Sed Contra

Sed contra est quod dicitur Eccli. XIII, omne animal diligit simile sibi.

Corpus

Respondeo dicendum quod similitudo, proprie loquendo, est causa amoris. Sed considerandum est quod similitudo inter aliqua potest attendi dupliciter. Uno modo, ex hoc quod utrumque habet idem in actu, sicut duo habentes albedinem, dicuntur similes.

Alio modo, ex hoc quod unum habet in potentia et in quadam inclinatione, illud quod aliud habet in actu, sicut si dicamus quod corpus grave existens extra suum locum, habet similitudinem cum corpore gravi in suo loco existenti. Vel etiam secundum quod potentia habet similitudinem ad actum ipsum, nam in ipsa potentia quodammodo est actus. Primus ergo similitudinis modus causat amorem amicitiae, seu benevolentiae. Ex hoc enim quod aliqui duo sunt similes, quasi habentes unam formam, sunt quodammodo unum in forma illa, sicut duo homines sunt unum in specie humanitatis, et duo albi in albedine. Et ideo affectus unius tendit in alterum, sicut in unum sibi; et vult ei bonum sicut et sibi. Sed secundus modus similitudinis causat amorem concupiscentiae, vel amicitiam utilis seu delectabilis. Quia unicuique existenti in potentia, inquantum huiusmodi, inest appetitus sui actus, et in eius consecutione delectatur, si sit sentiens et cognoscens.

Dictum est autem supra quod in amore concupiscentiae amans proprie amat seipsum, cum vult illud bonum quod concupiscit. Magis autem unusquisque seipsum amat quam alium, quia sibi unus est in substantia, alteri vero in similitudine alicuius formae.

Et ideo si ex eo quod est sibi similis in participatione formae, impediatur ipsemet a consecutione boni quod amat; efficitur ei odiosus, non inquantum est similis, sed inquantum est proprii boni impeditivus.

Et propter hoc figuli corrixantur ad invicem, quia se invicem impediunt in proprio lucro, et inter superbos sunt iurgia, quia se invicem impediunt in propria excellentia, quam concupiscunt.

Ad 1

Et per hoc patet responsio ad primum.

Ad 2

Ad secundum dicendum quod in hoc etiam quod aliquis in altero amat quod in se non amat, invenitur ratio similitudinis secundum proportionalitatem, nam sicut se habet alius ad hoc quod in eo amatur, ita ipse se habet ad hoc quod in se amat. Puta si bonus cantor bonum amet scriptorem, attenditur ibi similitudo proportionis, secundum quod uterque habet quod convenit ei secundum suam artem.

Ad 3

Ad tertium dicendum quod ille qui amat hoc quo indiget, habet similitudinem ad id quod amat sicut quod est potentia ad actum, ut dictum est.

Ad 4

Ad quartum dicendum quod secundum eandem similitudinem potentiae ad actum, ille qui non est liberalis, amat eum qui est liberalis, inquantum expectat ab eo aliquid quod desiderat. Et eadem ratio est de perseverante in amicitia ad eum qui non perseverat.

Utrobique enim videtur esse amicitia propter utilitatem. Vel dicendum quod, licet non omnes homines habeant huiusmodi virtutes secundum habitum completum, habent tamen ea secundum quaedam seminalia rationis, secundum quae, qui non habet virtutem, diligit virtuosum, tanquam suae naturali rationi conformem.