"Whoever desires that his intellect may grow up to soundness, to healthy vigor, must begin with moral discipline. Reading and study are not enough to perfect the power of thought. One thing above all is needful, and that is, the disinterestedness which is the very soul of virtue. To gain truth, which is the great object of the understanding, I must seek it disinterestedly. Here is the first and grand condition of intellectual progress. I must choose to receive the truth, no matter how it bears on myself. I must follow it, no matter where it leads, what interests it opposes, to what persecution or loss it lays me open, from what party it severs me, or to what party it allies. Without this fairness of mind, which is only another phrase for disinterested love of truth, great native powers of understanding are perverted and led astray."