FLUDD, ROBERT (called in Latin DE FLUCTINUS), an English physician and Rosicrucian philosopher, was the son of Sir Thomas Fludd, treasurer of war to Queen Elizabeth in France and the Low Countries, and was born at Milgate, Kent, in the year 1574. Blending the incomprehensible reveries of the Cabalists and Paracelsians, he formed a new physical system, replete with mystery and absurdity, and believed in two universal principles, the northern or condensing, and the southern or rarefying power. Innumerable geni, as he conceived, presided over these powers, and committed the charge of diseases to legions of spirits collected from the four winds of heaven. In his estimation, a harmony subsisted between the macrocosm and the microcosm, or the world of nature and the world of man. It is impossible to enumerate all his fancies and whims, which, however absurd and extravagant, being supported by mysterious gravity and the semblance of erudition, attracted the notice of the philosophers of that age. Even Kepler himself thought the preposterous jargon of Fludd worthy of refutation, and Gassendi with the same view wrote his Examen Philosophiae Fluddiana, 1629.
Fludd wrote two books against Mersenne, the first entitled Sophis cum Moria certamen, in quo lapis Lydus, a falso structore Patre Morino Mersenne monacho reprobat, celesterrima voluminis sui Babylonici in Genesim signata accurate examinat, Francfort, 1629, folio; and the second, Summum Bonorum quod est verum Magia, Cabala, Alchymia, Fratrum Rosae Crucis Verorum, Subiectum, etc. 1629, folio. His other works were, 1. Utriusque Corvi, majoris et minoris, Technica Historia, Appenheim, 1617, in 2 vols. folio; 2. Tractatus Apologeticus integritatem Soc. de Rosae Crucis defendens, Leyden, 1617; 3. Monochordon Mundi symphoniam, seu Replicatio ad Apologiam Joannis Kepleri, Francfort, 1620; 4. Anatomia Theatrum triplici effigie designatum, ibid. 1623; 5. Philosophia Sacra et vere Christiana, seu Meteorologia Cornica, ibid. 1626; 6. Medicina Catholica, seu mysticum artis medicandi sacrum, ibid. 1626; 7. Integrum Morborum mysterium, ibid. 1631; 8. De Morborum Signis, ibid. 1631; 9. Clariss. Philosophia et Alchymia Fluddiana, ibid. 1633; 10. Philosophia Moscaica, Gouda, 1638; and, 11. Pathologia Demonica, ibid. 1640.