“Many men (saith he) come to this malady by continual study, and night-waking, and of all other men, scholars are most subject to it: and such Rhasis adds, that have commonly the finest wits. Cont. lib. 1, tract. 9, Marsilius Ficinus, de sanit. tuenda, lib. 1. cap. 7, puts melancholy amongst one of those five principal plagues of students, ’tis a common Maul unto them all, and almost in some measure an inseparable companion. Varro belike for that cause calls Tristes Philosophos et severos, severe, sad, dry, tetric, are common epithets to scholars: and Patritius therefore, in the institution of princes, would not have them to be great students. For (as Machiavel holds) study weakens their bodies, dulls the spirits, abates their strength and courage; and good scholars are never good soldiers, which a certain Goth well perceived, for when his countrymen came into Greece, and would have burned all their books, he cried out against it, by no means they should do it, leave them that plague, which in time will consume all their vigour, and martial spirits. The Turks abdicated Cornutus the next heir from the empire, because he was so much given to his book: and ’tis the common tenet of the world, that learning dulls and diminisheth the spirits, and so per consequens produceth melancholy.”
-Robert Burton, The Anatomy of Melancholy Pt. 1 Sec. 2 Mem 3. Subs. 15