In idealist philosophy, the Absolute is "the sum of all being, actual and potential".^[1] In monistic idealism, it serves as a concept for the "unconditioned reality which is either the spiritual ground of all being or the whole of things considered as a spiritual unity.^[2]

The concept of "the absolute" was introduced in modern philosophy, notably by Hegel, for "the sum of all being, actual and potential".^[3][1] For Hegel, states the philosophy scholar Martin Heidegger, the Absolute is "the spirit, that which is present to itself in the certainty of unconditional self-knowing".^[4] According to Hegel, states Frederick Copleston – a historian of philosophy, "Logic studies the Absolute 'in itself'; the philosophy of Nature studies the Absolute 'for itself'; and the philosophy of Spirit studies the Absolute 'in and for itself'.^[5] The concept is also found in the works of F.W.J. Schelling, and was anticipated by Johann Gottlieb Fichte.^[2] In English philosophy, F. H. Bradley has distinguished the concept of Absolute from God, while Josiah Royce, the founder of American idealism school of philosophy, has equated them.^[2]

The concept of the Absolute has been used to interpret the early texts of the Indian religions such as those attributed to Yajnavalkya, Nagarjuna and Adi Shankara.^[6]

In Jainism, Absolute Knowledge or Kewalya Gnan, is said to be attained by the Arihantas and Teerthankaras, who reflects in their knowing, the 360 degrees of the truth and events of past, present and future. All 24 Teerthankaras and many others are Kewalya Gnani or Carriers of Absolute Knowledge.

According to Takeshi Umehara, some ancient texts of Buddhism state that the "truly Absolute and the truly Free must be nothingness",^[7] the "void".^[8] Yet, the early Buddhist scholar Nagarjuna, states Paul Williams, does not present "emptiness" as some kind of Absolute, rather it is "the very absence (a pure non-existence) of inherent existence" in Mādhyamaka school of the Buddhist philosophy.^[9]

According to Glyn Richards, the early texts of Hinduism state that the Brahman or the nondual Brahman–Atman is the Absolute.^[10][11][12]

The term has also been adopted by Aldous Huxley in his perennial philosophy to interpret various religious traditions, including Indian religions,^[13] and influenced other strands of nondualistic and New Age thought.