Actus humani recipiunt speciem a fine quia finis non est omnino aliquid extrinsecum ab actu, quia comparatur ad actum ut principium vel terminus; et hoc ipsum est de ratione actus, ut scilicet sit ab aliquo, quantum ad actionem, et ut sit ad aliquid, quantum ad passionem.
Human acts are specified by their end because the end is not altogether extrinsic to the act, because it is related to the act as principle or terminus; and thus it is just this that is the formal aspect of an act, viz. to proceed from something, considered as action, and to proceed towards something, considered as passion.
Unumquodque sortitur speciem secundum actum, et non secundum potentiam, unde ea quae sunt composita ex materia et forma, constituuntur in suis speciebus per proprias formas. Et hoc etiam considerandum est in motibus propriis. Cum enim motus quodammodo distinguatur per actionem et passionem, utrumque horum ab actu speciem sortitur, actio quidem ab actu qui est principium agendi; passio vero ab actu qui est terminus motus.
Each thing receives its species in respect of an act and not in respect of potentiality; wherefore things composed of matter and form are established in their respective species by their own forms. And this is also to be observed in proper movements. For since movements are, in a way, divided into action and passion, each of these receives its species from an act; action indeed from the act which is the principle of acting, and passion from the act which is the terminus of the movement.
Finis secundum quod est prior in intentione, ut dictum est, secundum hoc pertinet ad voluntatem. Et hoc modo dat speciem actui humano sive morali.
The end, insofar as it pre-exists in the intention, pertains to the will, as stated above (q1 ad 1). And it is thus that it gives the species to the human or moral act.
Idem actus numero, secundum quod semel egreditur ab agente, non ordinatur nisi ad unum finem proximum, a quo habet speciem, sed potest ordinari ad plures fines remotos, quorum unus est finis alterius.
One and the same act, insofar as it proceeds once from the agent, is ordained to but one proximate end, from which it has its species; but it can be ordained to several remote ends, of which one is the end of the other.