Petrarch, Secretum Book 3:
“What good has it been to know many things if you never learned how to accommodate them to your needs? For my part, I admired your error more in pursuing solitude, because you knew what the best authors among the ancients said against it, and you even added new ones. You complained often that solitude could do you no good, which you said in many places, especially in that poem which you wrote about your own condition. Meanwhile, as you sang, I was delighted by the sweetness of the song, and I was astounded because such a sweet sounding song sprang from your insane mouth in the middle of your spiritual storms, or I was astounded at what love could kept the Muses from fleeing from their accustomed house when they were assailed by such whirlwinds and such an alienation of their host. For, as Plato says, ‘one who is sane knocks on the doors of poetry in vain’, and as his successor Aristotle has it, ‘there is no great talent without some mixture of insanity.’ But these quotations apply to a different kind of insanity than yours; we shall discuss this later.”
