Editing Robert Fludd (section)

===Macrocosm–microcosm relationship===
Fludd's application of his mystically inclined tripartite theory to his philosophies of medicine and science was best illustrated through his conception of the [[Macrocosm and microcosm]] relationship. The divine light (the second of Fludd's primary principles) was the "active agent" responsible for creation. This informed the development of the world and the Sun, respectively. Fludd concluded, from a reading of Psalm 19:4—"In them hath he set a tabernacle for the sun"—that the Spirit of the Lord was contained literally within the Sun, placing it central to Fludd's model of the macrocosm.<ref name="William H. Huffman 146">{{cite book|author=William H. Huffman|title=Robert Fludd|url=https://books.google.com/books?id=pTAiTfP5jq4C&pg=PA146|year=2001|publisher=North Atlantic Books|isbn=978-1-55643-373-3|page=146}}</ref> remained in manuscript.<ref name="Debus, p. 255">Debus, p. 255.</ref> As the Sun was to the Earth, so was the heart to mankind. The Sun conveyed Spirit to the Earth through its rays, which circulated in and about the Earth giving it life. Likewise, the blood of man carried the Spirit of the Lord (the same Spirit provided by the Sun), and circulated through the body of man. This was an application of the sympathies and parallels provided to all of God's Creation by Fludd's tripartite theory of matter.

The blood was central to Fludd's conception of the relationship between the microcosm and macrocosm; the blood and the Spirit it circulated interacted directly with the Spirit conveyed to the macrocosm. The macrocosmal Spirit, carried by the Sun, was influenced by astral bodies and changed in composition through such influence. Comparatively, the astral influences on the macrocosmal Spirit could be transported to the microcosmal Spirit in the blood by the active commerce assumed between the macrocosm and the microcosm. Fludd extended this interaction to his conception of disease: the movement of Spirit between the macrocosm and microcosm could be corrupted and invade the microcosm as disease. Like Paracelsus, Fludd conceived of disease as an external invader, rather than a complexional imbalance.