5p41d.md (619B)
1 The first and only foundation of virtue, or the rule 2 of right living is (IV. xxii. Coroll. and xxiv.) seeking one's 3 own true interest. Now, while we determined what reason 4 prescribes as useful, we took no account of the mind's eternity, 5 which has only become known to us in this Fifth Part. Although 6 we were ignorant at that time that the mind is eternal, we 7 nevertheless stated that the qualities attributable to courage 8 and high–mindedness are of primary importance. Therefore, even 9 if we were still ignorant of this doctrine, we should yet put the 10 aforesaid precepts of reason in the first place. Q.E.D. 11 12