E4P52D
Demonstration — Part IV
Latin
Acquiescentia in se ipso est lætitia orta ex eo quod homo se ipsum suamque agendi potentiam contemplatur (per 25 affectuum definitionem). At vera hominis agendi potentia seu virtus est ipsa ratio (per propositionem 3 partis III) quam homo clare et distincte contemplatur (per propositiones 40 et 43 partis II). Ergo acquiescentia in se ipso ex ratione oritur. Deinde nihil homo dum se ipsum contemplatur, clare et distincte sive adæquate percipit nisi ea quæ ex ipsius agendi potentia sequuntur (per definitionem 2 partis III) hoc est (per propositionem 3 partis III) quæ ex ipsius intelligendi potentia sequuntur adeoque ex sola hac contemplatione summa quæ dari potest acquiescentia oritur. Q.E.D.
English (Elwes 1883)
Self--approval is pleasure arising from a man's contemplation of himself and his own power of action (Def. of the Emotions, xxv.). But a man's true power of action or virtue is reason herself (III. iii.), as the said man clearly and distinctly contemplates her (II. xl. xliii.); therefore self--approval arises from reason. Again, when a man is contemplating himself, he only perceived clearly and distinctly or adequately, such things as follow from his power of action (III. Def. ii.), that is (III. iii.), from his power of understanding; therefore in such contemplation alone does the highest possible self--approval arise. Q.E.D.
Modern English
Self-approval is joy arising from a person's contemplation of himself and his power of action (E3DA25). A person's true power of action — his virtue — is reason itself (E3P3), which he contemplates clearly and distinctly (E2P40). Self-approval therefore arises from reason.
When a person contemplates himself, he perceives clearly and distinctly — that is, adequately — only what follows from his power of action (E3D2), which is (E3P3) what follows from his power of understanding. So the highest possible self-approval arises from this contemplation alone. Q.E.D.