Monism is most commonly seen with Panentheism, and Immanent God. Pantheism is closely related to monism, since pantheists also view all of reality as one single substance, called the universe, God, or Nature. In this sense, Monism, being synonymous with pantheism, holds that there is no true distinction between but one reality and the universe. Another type of monism is called neutral monism, which holds that one thing, one substance of reality, is neither mental or physical, but is capable of being expressed by one things attributes.
This dual-aspect theory holds that existence is composed of one sort of primary substance (hence, monism) that is not mental or physical per se, but is capable of having both mental and physical aspects or attributes. All things are one, one primary substance; hence the term substance-monism. We will suppose there is a plurality of substantial things, and thus that monism is false. Substance-based monism holds that the diversity of existing things can be explained by means of a single reality, or substance.
Substance monism holds that there is a single type of substance, though a number of things may consist of that substance, such as matter or the mind. Existence monism posits that, strictly speaking, only one thing, the universe, exists, which can be only artificially and arbitrarily divided into many things. In contrast, Attributive Monism, represented by philosophers like Gottfried Leibniz (1646-1716), is a belief in a single category, a category which holds that there is just one type of things, whereas there are many distinct separate things or substances in this single category. Attributive monism is the view held by that there is only one substance, and there is only one Being, such as the ancient Hindu philosophy Advaita Vedanta.
Monism is a very broad term, applied to any doctrine which holds either that ultimately only one thing exists, or only one sort of thing exists; it has also been used for the view that there is only one true set of beliefs. Monism is the view that reality is composed of one basic, final essence. Monism is a metaphysical and theological view that everything is composed of a single fundamental essence, principle, substance, or energy. Monism is the philosophical view that all of reality can be reduced to one thing, or a substance. This view is contrasted with dualism (in which all reality is reducible to two substances, such as good and evil; light and dark; form and matter; body and soul) and pluralism (all of reality is composed of several substances).
Monism is often contrasted also with dualism, as much of philosophical discussion has focused on whether two distinct kinds of things, namely, mind and matter, exist, or just one. Wherever the dualist philosophy makes a distinction between body and soul, matter and spirit, object and subject, substance and power, a system that denies this distinction, reducing one of the terms in opposition to the other, or merging the two into one higher unity, is called Monism. The term Monism was introduced in the eighteenth century by Christian von Wolff in his book Logicism (1728), to describe types of philosophical thinking where an effort is made to remove the dichotomy between body and mind, and explain all phenomena either through one unitary principle, or as the manifestation of one single substance. The term monism was introduced in the 18th century by Christian von Wolff in his work Logic (1728 ), to designate types of philosophical thought in which the attempt was made to eliminate the dichotomy of body and mind and explain all phenomena by one unifying principle, or as manifestations of a single substance. The 17th-century Sephardic Jew Barukh Spinoza defined reality in terms of one single substance, calling this either God or Nature, while the 19th-century German idealist G. W. F. Hegel, whose conception of the absolute continues to occupy the position in the contemporary west, as a monistic system, and his conception of absolutes continues to occupy a position in modern Western philosophy.
An impressive early instance of monism is found in the thinking of Parmenides, who argued, in an obscure way, that reality can be composed only of a single, and immutable, substance, and that appearances of multiplicity are illusory. Parmenides, following an opposing path to Heraclitus (535-475 BCE), said that final reality can reside only in something which is immutable; for Parmenides, this is the Absolute Being. Moving away from a metaphysical analysis towards a more spiritual perspective, monism is the basic worldview of those who adhered to a form of pantheism.
Substantive monism, which is represented in religions like Hinduism and Buddhism in the East, and in philosophers like Baruch Spinoza in the West, holds that all of reality is reducible to a single substance, and that all variety of reality means merely the multiplicity of aspects or modes of that single substance. There is but one reality, unchanging and eternal, which some (including the ancient Hindu philosophers) called God (idealistic-spiritual monism), while others, like the pre-Socratic philosophers like Parmenides, are content with naming it the One, or the One. In addition to Idealistic Monism, there is also Materialistic Monism, which declares there is only one reality, that is, matter, regardless of whether matter is a conglomeration of atoms, the original, world-forming substance (the IONIANS SCHOOL OF PHILOSOPHY), or a supposedly cosmic nebula from which the world evolved.
Neutral monism, developed subsequently by such men as William James (1842-1910), was developed as the middle ground between materialism and idealism, holding that the single category of existence, within which every actual, distinct individual substance, is not either mental nor material, but neutral. In priority monism, only one thing is ontologically fundamental, or before everything else. Priority monism holds that all existing things come from one source distinct from themselves; for example, in neoplatonism, all things are deduced from the One. Priority monism is the doctrine that precisely a particular token of an object is fundamental, equivalent to the classic doctrine that a whole is before its (proper) parts.