Τὸ νικᾶν αὐτὸν αὑτὸν πασῶν νικῶν πρώτη τε καὶ ἀρίστη → The first and best victory is to conquer self.
accomplishing nothing: P. ἄπρακτος, P. and V. ἀνήνυτος.
useless: P. and V. μάταιος, κενός, ἄχρειος, ἀνωφελής; see useless.
fruitless: P. ἄκαρπος, V. ἀκάρπωτος.