Aristotle, Nicomachean Ethics
H. Rackham, Ed.

[21] We do not see men becoming expert physicians from a study of medical handbooks. Yet medical writers attempt to describe not only general courses of treatment, but also methods of cure and modes of treatment for particular sorts of patients, classified according to their various habits of body; and their treatises appear to be of value for men who have had practical experience, though they are useless for the novice. Very possibly therefore collections of laws and constitutions may be serviceable to students capable of studying them critically, and judging what measures are valuable or the reverse, and what kind of institutions are suited to what national characteristics. But those who peruse such compilations without possessing a trained faculty cannot be capable of judging them correctly, unless they do so by instinct, though they may very likely sharpen their political intelligence.