-- James V. Schall, S.J., “On The Will to Know The Truth: Newman on Why Men of Learning Often Do Not Believe”
Aristotle pointed out that a slight error in the beginning of some science or philosophical position would, if not corrected, lead to a great error in the end. That is, this error would continue in the intellectual community. Its disorder would be expanded, developed, organized; its implications would be carried out in reality. Great systems of errors are often based on a very narrow fault or error, one that seems, to recall Aristotle, small in the beginning. From truth, truth follows, but from error anything can follow, as an old saying went. And of course, even truth can be rejected, though always in the name of another claimed truth. . . .
Aristotle [also] said that our ability to see the truth often depends on our virtue. If we are disordered in our ends, in our choices, we will spend our lives not pursuing truth, but rather in shrewdly using our minds to justify what we want to do.