In 1489 Ficino published De vita libri tres, three books on the life of the learned, and it is the place where his translations stop being philology and become practice. The first two books are a regimen for scholars, whom he diagnoses as natural melancholics, born under Saturn as he was himself: diet, sleep, walks, music, and the management of the black bile that makes study possible and destroys the student. The third book, On Obtaining Life from the Heavens, is the dangerous one.
Drawing on the Picatrix, on al-Kindi's rays and on the Asclepius, it teaches how to draw down beneficial planetary influence through materials, scents, colours, talismans and above all music, songs fitted to the planets whose performance tempers the spirit. Ficino is anxious throughout to keep the operation natural: the influence is carried by the world spirit through sympathies in things, not begged from demons, and he protests, a little too often, that he describes rather than approves the talismans. The anxiety was warranted; he was delated to the papal curia in 1490 and needed influential friends to quiet the matter. The book became the most read manual of natural magic of the Renaissance, and its portrait of the scholar's saturnine temperament, curable by Jupiter's music and the greenery of Venus, is the distant ancestor of every later attempt to make melancholy a mark of genius.