Deep versed in books and shallow in himself. [ Milton ]

Many books,
Wise men have said, are wearisome; who reads
Incessantly, and to his reading brings not
A spirit and judgment equal or superior,
Uncertain and unsettled still remains -
Deep versed in books, and shallow in himself. [ Milton ]

He was a man
Versed in the world as pilot in his compass;
The needle pointed ever to that interest
Which was his loadstar; and he spread his sails
With vantage to the gale of others' passions. [ Ben Jonson ]

He who expects from a great name in politics, in philosophy, in art, equal greatness in other things, is little versed in human nature. Our strength lies in our weakness. The learned in books are ignorant of the world. He who is ignorant of books is often well acquainted with other things; for life is of the same length in the learned and unlearned; the mind cannot be idle; if it is not taken up with one thing, it attends to another through choice or necessity; and the degree of previous capacity in one class or another is a mere lottery. [ Hazlitt ]