The commentary of William Hazlitt, stumbled over in my random perusal of Barlett's Familiar Quotations (1939 edition):

Persons without education certainly do not want either acuteness or strength of mind in what concerns themselves, or in things immediately within their observations; but they have no power of abstraction, no general standard of taste, or scale of opinion. They see their objects always near, and never in the horizon. Hence arises that egotism which has been remarked as the characteristic of self-taught men. (from The Round Table)

It is better to be able neither to read nor write than to be able to do nothing else. (from On the Ignorance of the Learned)

We are not hypocrites in our sleep. (from On Dreams)