Electio non sit nisi possibilium quia ratio eligendi aliquid est ex hoc quod ducit ad finem; per id autem quod est impossibile, non potest aliquis consequi finem.
Choice is only of possible things because the formal aspect under which a thing is to be chosen is that it conduces to an end; but what is impossible cannot conduce to an end.
Cum obiectum voluntatis sit bonum apprehensum, hoc modo iudicandum est de obiecto voluntatis, secundum quod cadit sub apprehensione. Et ideo sicut quandoque voluntas est alicuius quod apprehenditur ut bonum, et tamen non est vere bonum; ita quandoque est electio eius quod apprehenditur ut possibile eligenti, quod tamen non est ei possibile.
Since the object of the will is the apprehended good, we must judge of the object of the will according as it is apprehended. And so, just as sometimes the will tends to something which is apprehended as good, and yet is not really good; so is choice sometimes made of something apprehended as possible to the chooser, and yet impossible to him.
Voluntas media est inter intellectum et exteriorem operationem, nam intellectus proponit voluntati suum obiectum, et ipsa voluntas causat exteriorem actionem. Sic igitur principium motus voluntatis consideratur ex parte intellectus, qui apprehendit aliquid ut bonum in universali, sed terminatio seu perfectio actus voluntatis attenditur secundum ordinem ad operationem, per quam aliquis tendit ad consecutionem rei; nam motus voluntatis est ab anima ad rem.
The will stands between the intellect and the external action: for the intellect proposes to the will its object, and the will causes the external action. Hence the principle of the movement in the will is to be found in the intellect, which apprehends something under the universal aspect of good, but the term or perfection of the will's act is to be observed in its relation to the action, whereby a man tends to the attainment of a thing; for the movement of the will is from the soul to the thing.
Et ideo perfectio actus voluntatis attenditur secundum hoc quod est aliquid bonum alicui ad agendum. Hoc autem est possibile. Et ideo voluntas completa non est nisi de possibili, quod est bonum volenti. Sed voluntas incompleta est de impossibili, quae secundum quosdam "velleitas" dicitur, quia scilicet aliquis vellet illud, si esset possibile. Electio autem nominat actum voluntatis iam determinatum ad id quod est huic agendum. Et ideo nullo modo est nisi possibilium.
Consequently the perfect act of the will is in respect of something that is good for one to do. Now this cannot be something impossible. Wherefore the complete act of the will is only in respect of what is possible and good for him that wills. But the incomplete act of the will is in respect of the impossible; and by some is called "velleity," because, to wit, one would will [vellet] such a thing, were it possible. But choice is an act of the will, fixed on something to be done by the chooser. And therefore it is by no means of anything but what is possible.