High Quality Content by WIKIPEDIA articles! Robert Fludd, also known as Robertus de Fluctibus (17 January 1574, Bearsted, Kent – 8 September 1637, London) was a prominent English Paracelsian physician, astrologer, mathematician, cosmologist, Qabalist, Rosicrucian apologist. He was not a member of the Rosicrucians, as often alleged, but he defended their thoughts in the Apologia Compendiaria of 1616.