E4P24D
Demonstration — Part IV
Latin
Ex virtute absolute agere nihil aliud est (per definitionem 8 hujus) quam ex legibus propriæ naturæ agere. At nos eatenus tantummodo agimus quatenus intelligimus (per propositionem 3 partis III). Ergo ex virtute agere nihil aliud in nobis est quam ex ductu rationis agere, vivere, suum esse conservare idque (per corollarium propositionis 22 hujus) ex fundamento suum utile quærendi. Q.E.D.
English (Elwes 1883)
To act absolutely in obedience to virtue is nothing else but to act according to the laws of one's own nature. But we only act, in so far as we understand (III. iii.): therefore to act in obedience to virtue is in us nothing else but to act, to live, or to preserve one's being in obedience to reason, and that on the basis of seeking what is useful for us (IV. xxii. Coroll.). Q.E.D.
Modern English
To act absolutely from virtue is nothing other (by Definition 8 of this Part (E4D8)) than to act by the laws of one's own nature. But we act only insofar as we understand (E3P3). Therefore to act from virtue is, for us, nothing other than to act, to live, and to preserve one's being under the guidance of reason — and that (by the Corollary to P22 of this Part (E4P22C)) on the basis of seeking what is advantageous to us. Q.E.D.