I can't explain the grammar of this. Can you?
I have never written a sentence this long!

In the heyday of youthful greediness and ambition, when the mind, dazzled by the vastness and variety of the universe, must needs know everything, or rather know about everything, at once and on the spot, too many are apt, as I have been in past years, to complain of Cambridge studies as too dry and narrow: but as time teaches the student, year by year, what is really required for an understanding of the objects with which he meets, he begins to find that his University, in as far as he has really received her teaching into himself, has given him, in her criticism, her mathematics, above all, in Plato, something which all the popular knowledge, the lectures and institutions of the day, and even good books themselves, cannot give, a boon more precious than learning; namely, the art of learning.