4p20d.md (412B)
1 Virtue is human power, which is defined solely by 2 man's essence (IV. Def. viii.), that is, which is defined solely 3 by the endeavour made by man to persist in his own being. 4 Wherefore, the more a man endeavours, and is able to preserve his 5 own being, the more is he endowed with virtue, and, consequently 6 (III. iv. and vi.), in so far as a man neglects to preserve his 7 own being, he is wanting in power. Q.E.D. 8 9