The De vita libri tres or Three Books on Life was written in the years 1480-1489 by Italian Platonist Marsilio Ficino. It was first circulated in manuscript form and then published in 1489. It was constantly in print through the middle of the seventeenth century.
De vita is a curious amalgam of philosophy, medicine, "natural magic" and astrology, and is possibly the first book ever written about the health of the intellectual and its peculiar concerns. Alongside beautiful passages explaining the immortality and divine source and nature of the soul, there are astrological charts and remedies, sly speeches from various Greek gods arguing with one another, philosophical digressions, hair-raising medieval prescriptions for various ills, attempts at reconciling the Neoplatonism of Plotinus with Christian scripture, and magical remedies and talismans.
Ficino was one of the major philosophical voices of the Italian Renaissance, but he was also a physician, and the son of a physician. De vita is an example of the medical thinking of the early Renaissance, steeped in Galen and Hippocrates and the theory of the four humors and their attendant Aristotelian qualities (e.g., hot, cold, moist,dry), but also beginning to align this viewpoint with the awakening sense of the archetypal significance of the pagan gods, derived from the first exposure in the West for many centuries to the dialogues of Plato and to the Hermetica. (Ficino was the first translator of Plato into Latin.)