Ecclesiastes 7:16

Be not righteous over much Here again we have a distinct reproduction of one of the current maxims of Greek thought, Μηδὲν ἀγὰν (Ne quid nimisNothing in excess) of Theognis 402, and of Chilon (Diog. Laert. i. 1, § 41). Even in that which is in itself good, virtue lies, as Aristotle had taught (Eth. Nicom. ii. 6. 7), in a mean between opposite extremes. Popular language has embodied the thought in the proverb, Summum jus, summa injuria. Even in the other sense of "righteousness," as meaning personal integrity, personal religion, there might be, as in the ideal of the Pharisees and Essenes and Stoics, the "vaulting ambition" that o'erleaps itself." And "what was true of righteousness was true also of speculative philosophy. The wisdom that will not be content to rest in ignorance of the unknowable is indeed unwisdom, and "fools rush in where angels fear to tread."

why shouldest thou destroy thyself? The primary meaning of the verb in the form used here is that of "being amazed, stunned, astonished," and may have been chosen to express the besotted and bedazed spiritual pride which St Paul paints by the participle "puffed up" (τυφωθεὶς) in 1 Timothy 3:5, and which was but too commonly the accompaniment of fancied excellence in knowledge or in conduct.