A number of Christian writers have examined the concept of pandeism (a belief that God created and then became the universe and ceased to exist as a separate and conscious entity), and these have generally found it to be inconsistent with core principles of Christianity. The Roman Catholic Church, for example, condemned the Periphyseon of John Scotus Eriugena, later identified by physicist and philosopher Max Bernhard Weinstein as presenting a pandeistic theology, as appearing to obscure the separation of God and creation. The Church similarly condemned elements of the thought of Giordano Bruno which Weinstein and others determined to be pandeistic.

From ancient times to the Enlightenment Eriugena

The philosophy of 9th century theologian Johannes Scotus Eriugena, who proposed that "God has created the world out of his own being", has been identified by various theologians as a form of pandeism.Guillermo Kerber, "Panentheism in Christian Ecotheology," Luca Valera, ed., Pantheism and Ecology: Cosmological, Philosophical, and Theological Perspectives (Springer Publishing, 2023), p. 219-220; ASIN: B0CJNC946L.Max Bernhard Weinstein, Welt- und Lebensanschauungen, Hervorgegangen aus Religion, Philosophie und Naturerkenntnis ("World and Life Views, Emerging From Religion, Philosophy and Perception of Nature") (1910), page 283-84. Max Bernhard Weinstein notes 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.Max Bernhard Weinstein, Welt- und Lebensanschauungen, Hervorgegangen aus Religion, Philosophie und Naturerkenntnis ("World and Life Views, Emerging From Religion, Philosophy and Perception of Nature") (1910), page 283-84 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."Moran, Dermot, "John Scottus Eriugena", The Stanford Encyclopedia of Philosophy (Fall 2008 Edition), Edward N. Zalta (ed.) 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."O'Meara, John J., "Introduction", The Mind of Eriugena, (John J. O'Meara and Ludwig Bieler, eds.), Dublin: Irish University Press 1973. The system of thought outlined is a combination of neo-Platonic mysticism, emanationism, and pantheism which Eriugena strove in vain to reconcile with Aristotelian 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." Turner, William. "John Scotus Eriugena." The Catholic Encyclopedia Vol. 5. New York: Robert Appleton Company, 1909. 30 June 2019 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.Max Bernhard Weinstein, Welt- und Lebensanschauungen, Hervorgegangen aus Religion, Philosophie und Naturerkenntnis ("World and Life Views, Emerging From Religion, Philosophy and Perception of Nature") (1910), page 303: "Andere Ganz- oder Halbmystiker, wie den Alanus (gegen 1200), seinerzeit ein großes Kirchenlicht und für die unseligen Waldenser von verhängnisvoller Bedeutung, den Bonaventura (1221 im Kirchenstaate geboren), der eine Reise des Geistes zu Gott geschrieben hat und stark pandeistische Neigungen zeigt, den Franzosen Johann Gersan (zu Gersan bei Rheims 1363 geboren) usf., übergehen wir, es kommt Neues nicht zum Vorschein." 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.Max Bernhard Weinstein, Welt- und Lebensanschauungen, Hervorgegangen aus Religion, Philosophie und Naturerkenntnis ("World and Life Views, Emerging From Religion, Philosophy and Perception of Nature") (1910), page 306: "Er ist bis zu einem gewissen Grade Pandeist. Gott schafft die Welt nur aus sich (de nullo alio creat, sed ex se); indem er alles umfaßt, entfaltet er alles aus sich, ohne doch sich dabei irgend zu verändern."

Giordano Bruno 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.Max Bernhard Weinstein, Welt- und Lebensanschauungen, Hervorgegangen aus Religion, Philosophie und Naturerkenntnis ("World and Life Views, Emerging From Religion, Philosophy and Perception of Nature") (1910), page 321 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.Review of Welt- und Lebensanschauungen, Hervorgegangen aus Religion, Philosophie und Naturerkenntnis ("World and Life Views, Emerging From Religion, Philosophy and Perception of Nature") in Emil Schürer, Adolf von Harnack, editors, Theologische Literaturzeitung ("Theological Literature Journal"), Volume 35, column 827 (1910). 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,"Powell, Corey S., "Defending Giordano Bruno: A Response from the Co-Writer of 'Cosmos' , Discover, March 13, 2014: "Bruno imagines all planets and stars having souls (part of what he means by them all having the same "composition"), and he uses his cosmology as a tool for advancing an animist or Pandeist theology." and this position was agreed with by science writer Michael Newton Keas, and The Daily Beast writer David Sessions.David Sessions, "How 'Cosmos' Bungles the History of Religion and Science", The Daily Beast, 03.23.14: "Bruno, for instance, was a 'pandeist', which is the belief that God had transformed himself into all matter and ceased to exist as a distinct entity in himself." Tariq Goddard wrote that "Bruno was not quite an atheist or pantheist. He most likely followed an apophatic creed (via negativa), making him more of a pandeist."Tariq Goddard, The Repeater Book of Heroism (2022), p. 25.

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:Luigi Firpo, Il processo di Giordano Bruno, 1993. 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.Discussed in Dorothea Waley Singer, Giordano Bruno, His Life and Thought, New York, 1950, ch. 7. 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. The Cambridge Companion to Joseph Ratzinger notes that Joseph Ratzinger, who would later become Pope, was in particular "critical of… [Bruno's] pandeism".Daniel Cardó, Uwe Michael Lang, Cambridge Companion to Joseph Ratzinger (2023), p. 266.

Post-Enlightenment developments In the 1800s In the 1820s to 1830s, pandeism received some mention in Italy. In 1832 and 1834, publishers Angelo Ajani and Giovanni Silvestri, respectively, each posthumously published volumes of sermons of Italian Padre Filippo Nannetti di Bibulano (aka il Filippo Nani, Padre da Lojano; 1759–1829), who named pandeism as being among beliefs he condemned, railing against "Jews, Muslims, Gentiles, Schismatics, Heretics, Pandeists, Deists, and troubled, restless spirits."Padre Filippo Nannetti di Bibulano (aka il Filippo Nani, Padre da Lojano), in Sermons and Panegyrics of the Father Filippo Nani of Lojana, Giovanni Silvestri, publisher, 1834, p. 284, Sermon XVIII: Miracles: "Ma questa religione predestinta col taumaturgo segnale si trova ella nel mondo i' Dove? in qual gente? in qual lido? Nelle sinagoghe giudaiche, o nelle meschìte dell l'Asia? Nelle pagoda cinesi, o nella società di Ginevra? Giudei, Maomettani, Gentili, Scismatici, Eretici, Pandeisti, Deisti, geni torbidi, e inquieti." ("But this religion predestined by the thaumaturgist signal, where in the world is she? in which people? on which shores? In Jewish synagogues, or mosques of Asia? Pagoda in Chinese, or in society in Geneva? Jews, Muslims, Gentiles, Schismatics, Heretics, Pandeists, Deists, and troubled, restless spirits.") Nannetti further specifically criticized pandeism, declaring, "To you, fatal Pandeist! the laws that create nature are contingent and mutable, not another being in substance with forces driven by motions and developments."Padre Filippo Nannetti di Bibulano (aka il Filippo Nani, Padre da Lojano), in Sermons and Panegyrics of the Father Filippo Nani of Lojana, Giovanni Silvestri, publisher, 1834, p. 286, Sermon XVIII: Miracles: "A te, fatal Pandeista! le leggi della creata natura son contingenti e mutabili; non altro essendo in sostanza che moti e sviluppi di forze motrici." In 1838, another Catholic Italian, phrenologist Luigi Ferrarese in Memorie Riguardanti la Dottrina Frenologica ("Thoughts Regarding the Doctrine of Phrenology") critically described Victor Cousin's philosophy as a doctrine which "locates reason outside the human person, declaring man a fragment of God, introducing a sort of spiritual pandeism, absurd for us, and injurious to the Supreme Being."

Towards the end of the century, in 1897, Reverend Henry Grattan Guinness wrote critically that in India, "God is everything, and everything is God, and, therefore, everything may be adored. ... Her pan-deism is a pandemonium."Henry Grattan Guinness, "First Impressions of India", in John Harvey Kellogg, and the International Health and Temperance Association's, The Medical Missionary (1897), pages 125-127.