Pantheism (Greek: πάν (pan) = all and θεός (theos) = God, literally "God is all" -ism) is the view that everything is part of an all-encompassing immanent God. In pantheism, the Universe (Nature) and God are considered equivalent and synonymous. More detailed definitions tend to emphasize the idea that God is better understood as an abstract principle representing natural law, existence, and the Universe (the sum total of all that was, is and shall be), rather than as an anthropomorphic entity.
Pantheism is non-theistic, but rarely atheistic. The term "pantheist"—from which the word "pantheism" is derived—was purportedly first used by Irish writer John Toland in his 1705 work, Socinianism Truly Stated, by a pantheist. However, the concept has been discussed as far back as the time of the philosophers of Ancient Greece, by Thales, Parmenides and Heraclitus.
The Jewish backgrounds for pantheism may reach as far back as the Torah itself in its account of creation in Genesis and its earlier prophetic material in which clearly "acts of nature" (such as floods, storms, volcanoes, etc.) are all identified as "God's hand" through personification idioms, thus explaining the open references to the concept in both New Testament and Kabbalistic literature. In 1785 a major controversy began between Friedrich Jacobi and Moses Mendelssohn, which eventually involved many important people of the time. Jacobi claimed that Gotthold Ephraim Lessing's pantheism was materialistic in that it thought of all Nature and God as one extended substance.
For Jacobi, this was the result of the Enlightenment's devotion to reason and it would lead to atheism. Mendelssohn disagreed by asserting that pantheism was the same as theism.