E4P14D
Demonstration — Part IV
Latin
Affectus est idea qua mens majorem vel minorem sui corporis existendi vim quam antea affirmat (per generalem affectuum definitionem) atque adeo (per propositionem 1 hujus) nihil positivum habet quod præsentia veri tolli possit et consequenter vera boni et mali cognitio quatenus vera nullum affectum coercere potest. At quatenus affectus est (vide propositionem 8 hujus) si fortior affectu coercendo sit, eatenus tantum (per propositionem 7 hujus) affectum coercere poterit. Q.E.D.
English (Elwes 1883)
An emotion is an idea, whereby the mind affirms of its body a greater or less force of existing than before (by the general Definition of the Emotions); therefore it has no positive quality, which can be destroyed by the presence of what is true; consequently the knowledge of good and evil cannot, by virtue of being true, restrain any emotion. But, in so far as such knowledge is an emotion (IV. viii.) if it have more strength for restraining emotion, it will to that extent be able to restrain the given emotion. Q.E.D.
Modern English
An affect is an idea by which the mind affirms of its body a greater or lesser force of existing than before (E3DA49), and so (E4P1) it has nothing positive that the presence of what is true could remove. Consequently, true knowledge of good and bad cannot, by virtue of being true, check any affect. But insofar as it is an affect (E4P8), if it is stronger than the affect to be checked, it will to that extent be able to check it (E4P7). Q.E.D.