In the next place, since our opponents keep repeating those statements about faith, we must say that, considering it as a useful thing for the multitude, we admit that we teach those men to believe without reasons, who are unable to abandon all other employments, and give themselves to an examination of arguments; and our opponents, although they do not acknowledge it, yet practically do the same. For who is there that, on betaking himself to the study of philosophy, and throwing himself into the ranks of some sect, either by chance, or because he is provided with a teacher of that school, adopts such a course for any other reason, except that he believes his particular sect to be superior to any other?
For, not waiting to hear the arguments of all the other philosophers, and of all the different sects, and the reasons for condemning one system and for supporting another, he in this way elects to become a Stoic, e.g., or a Platonist, or a Peripatetic, or an Epicurean, or a follower of some other school, and is thus borne, although they will not admit it, by a kind of irrational impulse to the practice, say of Stoicism, to the disregard of the others; despising either Platonism, as being marked by greater humility than the others; or Peripateticism, as more human, and as admitting with more fairness than other systems the blessings of human life.
And some also, alarmed at first sight about the doctrine of providence, from seeing what happens in the world to the vicious and to the virtuous, have rashly concluded that there is no divine providence at all, and have adopted the views of Epicurus and Celsus.
Source: Against Celsus (New Advent)