Thomas Aquinas, Summa Theologiae

Objection 1: It would seem possible for one man's will to be directed at the same time to several things, as last ends. For Augustine says (De Civ. Dei xix, 1) that some held man's last end to consist in four things, viz. "in pleasure, repose, the gifts of nature, and virtue." But these are clearly more than one thing. Therefore one man can place the last end of his will in many things.

Objection 2: Further, things not in opposition to one another do not exclude one another. Now there are many things which are not in opposition to one another. Therefore the supposition that one thing is the last end of the will does not exclude others.

Objection 3: Further, by the fact that it places its last end in one thing, the will does not lose its freedom. But before it placed its last end in that thing, e.g. pleasure, it could place it in something else, e.g. riches. Therefore even after having placed his last end in pleasure, a man can at the same time place his last end in riches. Therefore it is possible for one man's will to be directed at the same time to several things, as last ends.

On the contrary, That in which a man rests as in his last end, is master of his affections, since he takes therefrom his entire rule of life. Hence of gluttons it is written (Phil. 3:19): "Whose god is their belly": viz. because they place their last end in the pleasures of the belly. Now according to Mt. 6:24, "No man can serve two masters," such, namely, as are not ordained to one another. Therefore it is impossible for one man to have several last ends not ordained to one another.

I answer that, It is impossible for one man's will to be directed at the same time to diverse things, as last ends. Three reasons may be assigned for this. First, because, since everything desires its own perfection, a man desires for his ultimate end, that which he desires as his perfect and crowning good. Hence Augustine (De Civ. Dei xix, 1): "In speaking of the end of good we mean now, not that it passes away so as to be no more, but that it is perfected so as to be complete." It is therefore necessary for the last end so to fill man's appetite, that nothing is left besides it for man to desire. Which is not possible, if something else be required for his perfection. Consequently it is not possible for the appetite so to tend to two things, as though each were its perfect good.

The second reason is because, just as in the process of reasoning, the principle is that which is naturally known, so in the process of the rational appetite, i.e. the will, the principle needs to be that which is naturally desired. Now this must needs be one: since nature tends to one thing only. But the principle in the process of the rational appetite is the last end. Therefore that to which the will tends, as to its last end, is one.

The third reason is because, since voluntary actions receive their species from the end, as stated above (Article 3), they must needs receive their genus from the last end, which is common to them all: just as natural things are placed in a genus according to a common form. Since, then, all things that can be desired by the will, belong, as such, to one genus, the last end must needs be one. And all the more because in every genus there is one first principle; and the last end has the nature of a first principle, as stated above. Now as the last end of man, simply as man, is to the whole human race, so is the last end of any individual man to that individual. Therefore, just as of all men there is naturally one last end, so the will of an individual man must be fixed on one last end.

Reply to Objection 1: All these several objects were considered as one perfect good resulting therefrom, by those who placed in them the last end.

Reply to Objection 2: Although it is possible to find several things which are not in opposition to one another, yet it is contrary to a thing's perfect good, that anything besides be required for that thing's perfection.

Reply to Objection 3: The power of the will does not extend to making opposites exist at the same time. Which would be the case were it to tend to several diverse objects as last ends, as has been shown above (ad 2).

Articulus 5

Argumentum 1

Ad quintum sic proceditur. Videtur quod possibile sit voluntatem unius hominis in plura ferri simul, sicut in ultimos fines.

Dicit enim Augustinus, XIX de CIV. Dei, quod quidam ultimum hominis finem posuerunt in quatuor, scilicet in voluptate, in quiete, in primis naturae, et in virtute.

Haec autem manifeste sunt plura. Ergo unus homo potest constituere ultimum finem suae voluntatis in multis.

Argumentum 2

Praeterea, ea quae non opponuntur ad invicem, se invicem non excludunt. Sed multa inveniuntur in rebus quae sibi invicem non opponuntur. Ergo si unum ponatur ultimus finis voluntatis, non propter hoc alia excluduntur.

Argumentum 3

Praeterea, voluntas per hoc quod constituit ultimum finem in aliquo, suam liberam potentiam non amittit. Sed antequam constitueret ultimum finem suum in illo, puta in voluptate, poterat constituere finem suum ultimum in alio, puta in divitiis.

Ergo etiam postquam constituit aliquis ultimum finem suae voluntatis in voluptate, potest simul constituere ultimum finem in divitiis. Ergo possibile est voluntatem unius hominis simul ferri in diversa, sicut in ultimos fines.

Sed Contra

Sed contra, illud in quo quiescit aliquis sicut in ultimo fine, hominis affectui dominatur, quia ex eo totius vitae suae regulas accipit.

Unde de gulosis dicitur philipp. III, quorum deus venter est, quia scilicet constituunt ultimum finem in deliciis ventris.

Sed sicut dicitur Matth. VI, nemo potest duobus dominis servire, ad invicem scilicet non ordinatis. Ergo impossibile est esse plures ultimos fines unius hominis ad invicem non ordinatos.

Corpus

Respondeo dicendum quod impossibile est quod voluntas unius hominis simul se habeat ad diversa, sicut ad ultimos fines. Cuius ratio potest triplex assignari. Prima est quia, cum unumquodque appetat suam perfectionem, illud appetit aliquis ut ultimum finem, quod appetit, ut bonum perfectum et completivum sui ipsius.

Unde Augustinus dicit, XIX de CIV. Dei, finem boni nunc dicimus, non quod consumatur ut non sit, sed quod perficiatur ut plenum sit.

Oportet igitur quod ultimus finis ita impleat totum hominis appetitum, quod nihil extra ipsum appetendum relinquatur. Quod esse non potest, si aliquid extraneum ad ipsius perfectionem requiratur. Unde non potest esse quod in duo sic tendat appetitus, ac si utrumque sit bonum perfectum ipsius. Secunda ratio est quia, sicut in processu rationis principium est id quod naturaliter cognoscitur, ita in processu rationalis appetitus, qui est voluntas, oportet esse principium id quod naturaliter desideratur.

Hoc autem oportet esse unum, quia natura non tendit nisi ad unum.

Principium autem in processu rationalis appetitus est ultimus finis. Unde oportet id in quod tendit voluntas sub ratione ultimi finis, esse unum. Tertia ratio est quia, cum actiones voluntarie ex fine speciem sortiantur, sicut supra habitum est, oportet quod a fine ultimo, qui est communis, sortiantur rationem generis, sicut et naturalia ponuntur in genere secundum formalem rationem communem. Cum igitur omnia appetibilia voluntatis, inquantum huiusmodi, sint unius generis, oportet ultimum finem esse unum. Et praecipue quia in quolibet genere est unum primum principium, ultimus autem finis habet rationem primi principii, ut dictum est.

Sicut autem se habet ultimus finis hominis simpliciter ad totum humanum genus, ita se habet ultimus finis huius hominis ad hunc hominem. Unde oportet quod, sicut omnium hominum est naturaliter unus finis ultimus, ita huius hominis voluntas in uno ultimo fine statuatur.

Ad 1

Ad primum ergo dicendum quod omnia illa plura accipiebantur in ratione unius boni perfecti ex his constituti, ab his qui in eis ultimum finem ponebant.

Ad 2

Ad secundum dicendum quod, etsi plura accipi possint quae ad invicem oppositionem non habeant, tamen bono perfecto opponitur quod sit aliquid de perfectione rei extra ipsum.

Ad 3

Ad tertium dicendum quod potestas voluntatis non habet ut faciat opposita esse simul. Quod contingeret, si tenderet in plura disparata sicut in ultimos fines, ut ex dictis patet.