But the rational and the irrational appear such in a different way to different persons, just as the good and the bad, the profitable and the unprofitable. For this reason, particularly, we need discipline, in order to learn how to adapt the preconception of the rational and the irrational to the several things conformably to nature. But in order to determine the rational and the irrational, we use not only the of external things, but we consider also what is appropriate to each person.
