Origen

“ For as that man is “approved” in medicine who, on account of his experience in various (medical) heresies, and his honest examination of the majority of them, has selected the preferable system,—and as the great proficient in philosophy is he who, after acquainting himself experimentally with the various views, has given in his adhesion to the best,—so I would say that the wisest Christian was he who had carefully studied the heresies both of Judaism and Christianity. ”