The view that God and the universe are identical; or that there is no transcendent God outside the universe who created it, but the universe itself is divine.
Among philosophers, Baruch de Spinoza (1632-1677) is a prominent exponent of such a view, and it appears also in Stoicism.
The term itself was coined in 1705 by Irish writer John Toland (1670-1722).
Pantheism derives from the Greek πᾶν pan (meaning “all, of everything”) and θεός theos (meaning “god, divine”). The first known combination of these roots appears in Latin, in Joseph Raphson’s 1697 book De Spatio Reali seu Ente Infinito, where he refers to the “pantheismus” of Spinoza and others. It was subsequently translated into English as “pantheism” in 1702.
There are numerous definitions of pantheism. Some consider it a theological and philosophical position concerning God.:p.8
Pantheism is the view that everything is part of an all-encompassing, immanent God. All forms of reality may then be considered either modes of that Being, or identical with it. Some hold that pantheism is a non-religious philosophical position. To them, pantheism is the view that the Universe (in the sense of the totality of all existence) and God are identical (implying a denial of the personality and transcendence of God).
Early traces of pantheist thought can be found within the theology of the ancient Greek religion of Orphism, where pan (the all) is made cognate with the creator God Phanes (symbolizing the universe), and with Zeus, after the swallowing of Phanes.
Pantheistic tendencies existed in a number of early Gnostic groups, with pantheistic thought appearing throughout the Middle Ages. These included a section of Johannes Scotus Eriugena’s 9th-century work De divisione naturae and the beliefs of mystics such as Amalric of Bena (11th–12th centuries) and Eckhart (12th–13th).:pp. 620–621
The Catholic Church has long regarded pantheistic ideas as heresy. Giordano Bruno, an Italian monk who evangelized about a transcendent and infinite God, was burned at the stake in 1600 by the Roman Inquisition. He has since become known as a celebrated pantheist and martyr of science, and an influence on many later thinkers.
In the West, pantheism was formalized as a separate theology and philosophy based on the work of the 17th-century philosopher Baruch Spinoza.:p.7 Spinoza was a Dutch philosopher of Portuguese descent raised in the Sephardi Jewish community in Amsterdam. He developed highly controversial ideas regarding the authenticity of the Hebrew Bible and the nature of the Divine, and was effectively excluded from Jewish society at age 23, when the local synagogue issued a herem against him. A number of his books were published posthumously, and shortly thereafter included in the Catholic Church’s Index of Forbidden Books. The breadth and importance of Spinoza’s work would not be realized for many years – as the groundwork for the 18th-century Enlightenment and modern biblical criticism, including modern conceptions of the self and the universe.
In the posthumous Ethics, “Spinoza wrote the last indisputable Latin masterpiece, and one in which the refined conceptions of medieval philosophy are finally turned against themselves and destroyed entirely.” In particular, he opposed René Descartes’ famous mind–body dualism, the theory that the body and spirit are separate. Spinoza held the monist view that the two are the same, and monism is a fundamental part of his philosophy. He was described as a “God-intoxicated man,” and used the word God to describe the unity of all substance. This view influenced philosophers such as Georg Wilhelm Friedrich Hegel, who said, “You are either a Spinozist or not a philosopher at all.” Spinoza earned praise as one of the great rationalists of 17th-century philosophy and one of Western philosophy’s most important thinkers. Although the term “pantheism” was not coined until after his death, he is regarded as the most celebrated advocate of the concept. Ethics was the major source from which Western pantheism spread.
Heinrich Heine, in his Concerning the History of Religion and Philosophy in Germany (1833–36), remarked that “I don’t remember now where I read that Herder once exploded peevishly at the constant preoccupation with Spinoza, “If Goethe would only for once pick up some other Latin book than Spinoza!” But this applies not only to Goethe; quite a number of his friends, who later became more or less well-known as poets, paid homage to pantheism in their youth, and this doctrine flourished actively in German art before it attained supremacy among us as a philosophic theory.”
Johann Wolfgang von Goethe rejected Jacobi’s personal belief in God as the “hollow sentiment of a child’s brain” (Goethe 15/1: 446) and, in the “Studie nach Spinoza” (1785/86), proclaimed the identity of existence and wholeness. When Jacobi speaks of Spinoza’s “fundamentally stupid universe” (Jacobi  2000: 312), Goethe praises nature as his “idol” (Goethe 14: 535).
In their The Holy Family (1844) Karl Marx and Friedrich Engels notes, “Spinozism dominated the eighteenth century both in its later French variety, which made matter into substance, and in deism, which conferred on matter a more spiritual name…. Spinoza’s French school and the supporters of deism were but two sects disputing over the true meaning of his system….”
In George Henry Lewes’s words (1846), “Pantheism is as old as philosophy. It was taught in the old Greek schools — by Plato, by St. Augustine, and by the Jews. Indeed, one may say that Pantheism, under one of its various shapes, is the necessary consequence of all metaphysical inquiry, when pushed to its logical limits; and from this reason do we find it in every age and nation. The dreamy contemplative Indian, the quick versatile Greek, the practical Roman, the quibbling Scholastic, the ardent Italian, the lively Frenchman, and the bold Englishman, have all pronounced it as the final truth of philosophy. Wherein consists Spinoza’s originality? — what is his merit? — are natural questions, when we see him only lead to the same result as others had before proclaimed. His merit and originality consist in the systematic exposition and development of that doctrine — in his hands, for the first time, it assumes the aspect of a science. The Greek and Indian Pantheism is a vague fanciful doctrine, carrying with it no scientific conviction; it may be true — it looks true — but the proof is wanting. But with Spinoza there is no choice: if you understand his terms, admit the possibility of his science, and seize his meaning; you can no more doubt his conclusions than you can doubt Euclid; no mere opinion is possible, conviction only is possible.”
S. M. Melamed (1933) noted, “It may be observed, however, that Spinoza was not the first prominent monist and pantheist in modern Europe. A generation before him Bruno conveyed a similar message to humanity. Yet Bruno is merely a beautiful episode in the history of the human mind, while Spinoza is one of its most potent forces. Bruno was a rhapsodist and a poet, who was overwhelmed with artistic emotions; Spinoza, however, was spiritus purus and in his method the prototype of the philosopher.”
The first known use of the term “pantheism” was in Latin (“pantheismus” ) by the English mathematician Joseph Raphson in his work De Spatio Reali seu Ente Infinito, published in 1697. Raphson begins with a distinction between atheistic “panhylists” (from the Greek roots pan, “all”, and hyle, “matter”), who believe everything is matter, and Spinozan “pantheists” who believe in “a certain universal substance, material as well as intelligence, that fashions all things that exist out of its own essence.” Raphson thought that the universe was immeasurable in respect to a human’s capacity of understanding, and believed that humans would never be able to comprehend it. He referred to the pantheism of the Ancient Egyptians, Persians, Syrians, Assyrians, Greek, Indians, and Jewish Kabbalists, specifically referring to Spinoza.
The term was first used in English by a translation of Raphson’s work in 1702. It was later used and popularized by Irish writer John Toland in his work of 1705 Socinianism Truly Stated, by a pantheist.:pp. 617–618 Toland was influenced by both Spinoza and Bruno, and had read Joseph Raphson’s De Spatio Reali, referring to it as “the ingenious Mr. Ralphson’s (sic) Book of Real Space”. Like Raphson, he used the terms “pantheist” and “Spinozist” interchangeably. In 1720 he wrote the Pantheisticon: or The Form of Celebrating the Socratic-Society in Latin, envisioning a pantheist society that believed, “All things in the world are one, and one is all in all things … what is all in all things is God, eternal and immense, neither born nor ever to perish.” He clarified his idea of pantheism in a letter to Gottfried Leibniz in 1710 when he referred to “the pantheistic opinion of those who believe in no other eternal being but the universe”.
In the mid-eighteenth century, the English theologian Daniel Waterland defined pantheism this way: “It supposes God and nature, or God and the whole universe, to be one and the same substance—one universal being; insomuch that men’s souls are only modifications of the divine substance.” In the early nineteenth century, the German theologian Julius Wegscheider defined pantheism as the belief that God and the world established by God are one and the same.
Between 1785–89, a major controversy about Spinoza’s philosophy arose between the German philosophers Friedrich Heinrich Jacobi (a critic) and Moses Mendelssohn (a defender). Known in German as the Pantheismusstreit (pantheism controversy), it helped spread pantheism to many German thinkers. A 1780 conversation with the German dramatist Gotthold Ephraim Lessing led Jacobi to a protracted study of Spinoza’s works. Lessing stated that he knew no other philosophy than Spinozism. Jacobi’s Über die Lehre des Spinozas (1st ed. 1785, 2nd ed. 1789) expressed his strenuous objection to a dogmatic system in philosophy, and drew upon him the enmity of the Berlin group, led by Mendelssohn. Jacobi claimed that Spinoza’s doctrine was pure materialism, because all Nature and God are said to be nothing but extended substance. This, for Jacobi, was the result of Enlightenment rationalism and it would finally end in absolute atheism. Mendelssohn disagreed with Jacobi, saying that pantheism shares more characteristics of theism than of atheism. The entire issue became a major intellectual and religious concern for European civilization at the time.
Willi Goetschel argues that Jacobi’s publication significantly shaped Spinoza’s wide reception for centuries following its publication, obscuring the nuance of Spinoza’s philosophic work