Meyer and Weiss make no distinction between δικαίου and ἀγαθοῦ here. Most have held (I think, rightly) that the latter expresses more than the former. It comprehends those qualities of benevolence, kindness, etc., which may be considered as the peculiar bonds of friendship and would lead to the greatest sacrifices. Holman, Godet and Weiss (following Jerome) take τοῦ ἀγαθοῦ as neuter. J. Müller supposes it to refer to God. The force of the argument is: For an upright man one would hardly be moved to die, but in the case of a benefactor to whom one owed much, the motives of love and pity might move one strongly enough to lead him to summon up the resolution (τολμᾷ) to die, but this would be the highest and a very improbable reach of human love. But Christ died for his enemies, etc.—G.B.S.