Ratio potest ordinare de actu voluntatis, quia sicut potest iudicare quod bonum sit aliquid velle, ita potest ordinare imperando quod homo velit.
Formal aspect can direct the act of the will, because just as it can judge what good it is to will something, so it can direct, by commanding, what a man wills.
Imperium nihil aliud est quam actus rationis ordinantis, cum quadam motione, aliquid ad agendum.
Command is nothing else than the act of aspectual apprehension that directs, with a certain motion, something to be actualized.
Sicut Augustinus ibidem dicit, animus, quando perfecte imperat sibi ut velit, tunc iam vult; sed quod aliquando imperet et non velit, hoc contingit ex hoc quod non perfecte imperat.
As Augustine says (Confess. viii, 9) when the mind commands itself perfectly to will, then already it wills; but that sometimes it commands and wills not, is due to the fact that it commands imperfectly.
Imperfectum autem imperium contingit ex hoc, quod ratio ex diversis partibus movetur ad imperandum vel non imperandum: unde fluctuat inter duo, et non perfecte imperat.
Now imperfect command arises from the fact that aspectual apprehension is moved by opposite motives to command or not to command: wherefore it fluctuates between the two, and fails to command perfectly.
Sicut in membris corporalibus quodlibet membrum operatur non sibi soli, sed toti corpori (ut oculus videt toti corpori), ita etiam est in potentiis animae. Nam intellectus intelligit non solum sibi, sed omnibus potentiis; et voluntas vult non solum sibi, sed omnibus potentiis. Et ideo homo imperat sibi ipsi actum voluntatis, inquantum est intelligens et volens.
Just as each of the members of the body works not for itself alone but for the whole body (thus it is for the whole body that the eye sees), so is it with the powers of the soul. For the intellect understands, not for itself alone, but for all the powers; and the will wills not only for itself, but for all the powers too. Wherefore man, insofar as he is endowed with intellect and will, commands the act of the will for himself.
Cum imperium sit actus rationis, ille actus imperatur, qui rationi subditur. Primus autem voluntatis actus non est ex rationis ordinatione, sed ex instinctu naturae, aut superioris causae, ut supra dictum est. Et ideo non oportet quod in infinitum procedatur.
Since command is an act of aspectual apprehension, that act is commanded which is subject to formal aspect. Now the first act of the will is not due to the direction of formal aspect, but due to biological imperatives, or due to a higher cause, as stated above (q9 a4). Therefore there is no need to proceed to infinity.