The Italian religious reformer Girolamo Savonarola (1452-1498) became dictator of Florence in the 1490s and instituted there, in the middle of the Renaissance, a reign of purity and asceticism.

Girolamo Savonarola was born in Ferrara on Sept. 21, 1452. He was the third of seven children of Niccolo Savonarola, a physician, and Elena Bonacossi. His father groomed Girolamo for the medical profession, but even as a youth he took more interest in the writings of the Schoolmen, particularly Thomas Aquinas. Savonarola had time for neither the comfortable, courtly life of his father's household nor youthful sports and exercises, so absorbed was he in the subtleties of the scholastics and their spiritual father, Aristotle.

Repelled by the corruption of the world around him, Savonarola withdrew ever further into solitude, meditation, and prayer. In 1475 he entered a Dominican monastery at Bologna. After living quietly there for 6 years, Savonarola transferred to the convent...