Mbh 12.235.1d

One who is well-versed in the truths of the Vedas and the other branches of knowledge, whose behaviour is like that of a person of well-governed soul, who is endued with a clear vision, who observes those duties that are laid down for his order, who does not, by his acts, produce an inter-mixture of duties, who attends to the observances set down in the scriptures, who is full of faith, who is self-restrained, who is possessed of wisdom, who is destitute of envy and malice, and who is well-conversant with the distinctions between righteousness and inequity, succeeds in crossing all his difficulties. That Brahmana who is possessed of fortitude, who is always heedful, who is self-restrained, who is conversant with righteousness, whose soul is under control, and who has transcended joy, pride, and wrath, has never to languish in grief. This is the course of conduct that was ordained of old for a Brahmana. He should strive for the acquisition of Knowledge, and do all the scriptural acts. By living thus, he is sure to obtain success. One who is not possessed of clear vision does wrong even when one wishes to do right. Such a person, by even exercising his judgment, does such acts of virtue as partake of the nature of inequity. Desiring to do what is right, one does what is wrong. Similarly, desiring to do what is wrong one does what is right. Such a person is a fool. Not knowing the two kinds of acts, one has to undergo repeated rebirths and deaths.'"'"