He brought to literary researches the same vigour and amplitude of mind to which both physical and metaphysical science are so greatly indebted.

His fundamental principles of criticism are excellent.

To cite only a single instance:--the doctrine which he established, that poetry is an imitative art, when justly understood, is to the critic what the compass is to the navigator.

With it he may venture upon the most extensive excursions.

Without it he must creep cautiously along the coast, or lose himself in a trackless expanse, and trust, at best, to the guidance of an occasional star.