4p71d.md (326B)
1 Only free men are thoroughly useful one to another, 2 and associated among themselves by the closest necessity of 3 friendship (IV. xxxv., and Coroll. i.), only such men endeavour, 4 with mutual zeal of love, to confer benefits on each other (IV. 5 xxxvii.), and, therefore, only they are thoroughly grateful one 6 to another. Q.E.D. 7 8