Robert Fludd (born 1574, Bearsted, Kent, Eng.—died Sept. 8, 1637, London) was a British physician, author, and mystical philosopher remembered for his occultist opposition to science.

The son of Sir Thomas Fludd, he studied at St. John’s College, Oxford, before traveling in Europe for six years. On his return to Oxford he earned medical degrees (1605) and joined the College of Physicians (1609). He eventually became a prosperous London doctor.

Most of Fludd’s writings represent the culmination of the occult, as distinct from the scientific, tendencies of the 17th century. Deriving his ideas from such diverse sources as the Old Testament, the Jewish Kabbala, alchemy, astrology, sympathetic magic, and chiromancy, Fludd was primarily interested in establishing parallelisms between man and the world, both of which he viewed as images of God. The experimental observations in Fludd’s works are few, and their general tendency is opposed to the growing rationalism and scientific approach of his time. In his view, medicine’s role is to understand the functioning and malfunctioning of the human body by clues provided, for example, by parallelisms between the mind of man and the light of the Sun. The special analogies revealed by astrology and numerology were used to provide other medical insights. In his time Fludd was criticized widely as a magician and for his occult beliefs.