A person should never wait upon these six worst of men, viz., one that is a foe, one that always errs, one that is wedded to falsehood, one that is wanting in devotion to the gods, one that is without affection, and one that always regards himself competent to do everything. One’s purposes depend (for their success) on means; and means are dependent, again, on the nature of the purposes (sought to be accomplished by them). They are intimately connected with each other, so that success depends on both.

In plain words: Do not serve six kinds of bad people: an enemy, someone always making mistakes, a liar, someone with no faith, someone without affection, and someone who thinks he can do everything. Vidura also says your goals and the means you use depend on each other. Success needs both.