But how do our “senses” become “exercised”? By continual hearing; by experience of the Scriptures. For when we set forth the error of those [Heretics], and thou hearest today and to-morrow; and provest that it is not right, thou hast learnt the whole, thou hast known the whole: and even if thou shouldest not comprehend to-day, thou wilt comprehend to-morrow.