From ancient times to the Enlightenment
Max Bernhard Weinstein examined the philosophy of 9th century Irish theologian Johannes Scotus Eriugena, who proposed that "God has created the world out of his own being", and identified this as a form of pandeism, noting in particular that Eriugena's vision of God was one which does not know what it is, and learns this through the process of existing as its creation. In his magnum opus, De divisione naturae (also called Periphyseon, probably completed around 867 AD), Eriugena viewed creation as the self-manifestation of God. "God knows that He is, but not what He is. God has existential knowledge, but no circumscribing knowledge of His essence, since, as infinite, He is uncircumscribable.". According to Dermot Moran, "Eriugena's cosmological account has been criticized for collapsing the differences between God and creation, leading to a heresy later labeled as pantheism."
Eriugena himself denied explicitly that he was a pantheist. "God is all in all. All things that are in God, even are God, are eternal...the creature subsists in God, and God is created in the creature in a wonderful and ineffable way, making himself manifest, invisible making himself visible...But the divine nature, he finally insists, because it is above being, is different from what it create within itself." The system of thought outlined is a combination of neo-Platonic mysticism, emanationism, and pantheism which Eriugena strove in vain to reconcile with Aristotelean empiricism, Christian creationism, and theism. "The result is a body of doctrines loosely articulated, in which the mystic and idealistic elements predominate, and in which there is much that is irreconcilable with Catholic dogma." De divisione naturae was condemned by a council at Sens by Honorius III (1225), for promoting the identity of God and creation.
Weinstein also found that thirteenth century scholastic theologian and philosopher Bonaventure, who accepted the neo-Platonic doctrine that "forms" do not exist as subsistent entities, but as ideals or archetypes in the mind of God, according to which actual things were formed, showed strong pandeistic inclinations. Of Papal legate Nicholas of Cusa, who wrote of the enfolding of creation in God and the unfolding of the divine human mind in creation, Weinstein wrote that he was, to a certain extent, a pandeist.
Weinstein found that pandeism was strongly expressed in the teachings of Giordano Bruno, who envisioned a deity which had no particular relation to one part of the infinite universe more than any other, and was immanent, as present on Earth as in the Heavens, subsuming in itself the multiplicity of existence. Lutheran theologian Otto Kirn criticized as overbroad Weinstein's assertions that figures including Eriugena, Anselm of Canterbury, Nicholas of Cusa, Bruno, and Mendelssohn all were pandeists or leaned towards pandeism. Weinstein was not alone in considering Bruno a pandeist. Discover editor Corey S. Powell wrote that Bruno's cosmology was "a tool for advancing an animist or Pandeist theology," and this position was agreed with by science writer Micharl Newton Keas, and The Daily Beast writer David Sessions.
The Venetian Inquisition had Bruno arrested on 22 May 1592. Among the numerous charges of blasphemy and heresy brought against him in Venice, based on Mocenigo's denunciation, was his belief in the plurality of worlds, as well as accusations of personal misconduct. The Roman Inquisition, asked for his transfer to Rome, where he was sent in February 1593. The numerous charges against Bruno, based on some of his books as well as on witness accounts, included blasphemy, immoral conduct, and heresy in matters of dogmatic theology, and involved some of the basic doctrines of his philosophy and cosmology. Luigi Firpo speculates the charges made against Bruno by the Roman Inquisition were: holding opinions contrary to the Catholic faith and speaking against it and its ministers; holding opinions contrary to the Catholic faith about the Trinity, divinity of Christ, and Incarnation; the virginity of Mary, mother of Jesus; about both Transubstantiation and Mass; claiming the Eternity of the world; believing in metempsychosis and in the transmigration of the human soul into brutes; and dealing in magics and divination.
On 20 January 1600, Pope Clement VIII declared Bruno a heretic and the Inquisition issued a sentence of death. He was turned over to the secular authorities. On Ash Wednesday, 17 February 1600, in the Campo de' Fiori (a central Roman market square), and burned at the stake. All of Bruno's works were placed on the Index Librorum Prohibitorum in 1603. After a seven year trial there, he was put to death.