Recommended edition: Some Thoughts Concerning Education, ed. Ruth Grant and Nathan Tarcov (Indianapolis: Hackett, 1996).

Excerpt:

The last resort a man has recourse to, in the conduct of himself, is his understanding: for though we distinguish the faculties of the mind, and give the supreme command to the will, as to an agent; yet the truth is, the man, who is the agent, determines himself to this, or that, voluntary action, upon some precedent knowledge, or appearance of knowledge, in the understanding. No man ever sets himself about any thing, but upon some view or other, which serves him for a reason for what he does: and whatsoever faculties he employs, the understanding, with such light as it has, well or ill informed, constantly leads; and by that light, true or false, all his operative powers are directed. The will itself, how absolute and uncontrollable soever it may be thought, never fails in its obedience to the dictates of the understanding. Temples have their sacred images, and we see what influence they have always had over a great part of mankind. But, in truth, the ideas and images in men’s minds are the invisible powers, that constantly govern them; and to these they all universally pay a ready submission. It is, therefore, of the highest concernment, that great care should be taken of the understanding, to conduct it right, in the search of knowledge, and in the judgments it makes.

The logic, now in use, has so long possessed the chair, as the only art taught in the schools, for the direction of the mind, in the study of the arts and sciences, that it would perhaps be thought an affectation of novelty to suspect, that rules, that have served the learned world these two or three thousand years, and which, without any complaint of defects, the learned have rested in, are not sufficient to guide the understanding. … There is, it is visible, great variety in men’s understandings, and their natural constitutions put so wide a difference between some men, in this respect, that art and industry would never be able to master; and their very natures seem to want a foundation to raise on it that which other men easily attain unto.—Amongst men of equal education there is great inequality of parts. And the woods of America, as well as the schools of Athens, produce men of several abilities in the same kind. Though this be so, yet I imagine most men come very short of what they might attain unto, in their several degrees, by a neglect of their understandings. A few rules of logic are thought sufficient, in this case, for those who pretend to the highest improvement; whereas I think there are a great many natural defects in the understanding, capable of amendment, which are overlooked and wholly neglected. And it is easy to perceive, that men are guilty of a great many faults, in the exercise and improvement of this faculty of the mind, which hinder them in their progress, and keep them in ignorance and errour all their lives. Some of them I shall take notice of, and endeavour to point out proper remedies for, in the following discourse.

Online:
Online Library of Liberty (Free Version)
Amazon (Recommended Edition)