25-1
诚者自成也，而道自道也。
Sincerity is that whereby self-completion is effected, and its way is that by which man must direct himself.
第25章Chapter 25
25-2
诚者物之终始，不诚无物。是故君子诚之为贵。
Sincerity is the end and beginning of things; without sincerity there would be nothing. On this account, the superior man regards the attainment of sincerity as the most excellent thing.
25-3
诚者非自成己而已也，所以成物也。成己，仁也；成物，知也。性之德也，合外内之道也，故时措之宜也。
The possessor of sincerity does not merely accomplish the self-completion of himself. With this quality he completes other men and things also. The completing himself shows his perfect virtue. The completing other men and things shows his knowledge. But these are virtues belonging to the nature, and this is the way by which a union is effected of the external and internal. Therefore, whenever he-the entirely sincere man-employs them,-that is, these virtues, their action will be right.