Besides the pleasure derived from acquired knowledge, there lurks in the mind of man, and tinged with a shade of sadness, an unsatisfactory longing for something beyond the present, a striving towards regions yet unknown and unopened.
Wilhelm von HumboldtIf we glance at the most important revolutions in history, we see at once that the greatest number of these originated in the periodical revolutions of the human mind.
Wilhelm von HumboldtAll situations in which the interrelationships between extremes are involved are the most interesting and instructive.
Wilhelm von Humboldt