Prajnanam Brahma is a concept in Hindu philosophy that translates to "consciousness is Brahman" or "the ultimate reality is consciousness." This idea is found in the Aitareya Upanishad, which is one of the oldest Upanishads, and is part of the Rigveda, one of the four sacred texts of Hinduism.
The Aitareya Upanishad starts with the question of what the ultimate reality is, and it answers this question by stating that consciousness is the ultimate reality. It states that consciousness is not just something that exists within humans, but rather it is the very essence of existence itself. This idea is reinforced throughout the Upanishad, with statements such as "That from which all speech, along with the mind, turns away, unable to reach it - that indeed is the Brahman, the Atman (soul, self)." (Aitareya Upanishad 3.1.3)
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Prajnanam Brahma is closely related to the concept of Advaita Vedanta, which is a non-dualistic philosophy that holds that there is only one ultimate reality, and that all individual souls are ultimately one with this ultimate reality. According to Advaita Vedanta, the ultimate reality is not an object or a thing, but rather it is a state of consciousness. This state of consciousness is often referred to as "Self-realization" or "Atman-realization."
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In the Aitareya Upanishad, Prajnanam Brahma is described as the "inner controller" (Aitareya Upanishad 3.3.1) or "the ruler of all" (Aitareya Upanishad 3.3.2). It is said to be the source of all knowledge and the source of all creation. The Upanishad states that Prajnanam Brahma is not something that can be seen or touched, but rather it is something that can be known or experienced through self-realization.
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The Aitareya Upanishad also states that Prajnanam Brahma is the ultimate goal of human existence. It states that the ultimate goal of human life is to achieve self-realization, and that once this goal is achieved, one is freed from the cycle of birth and death. It states that "when a person becomes one with the Atman, they become immortal" (Aitareya Upanishad 3.4.1).
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In conclusion, Prajnanam Brahma is a central concept in Hindu philosophy, and it is found in the Aitareya Upanishad. According to this concept, consciousness is the ultimate reality, and the ultimate goal of human existence is to achieve self-realization and become one with the ultimate reality. This concept is closely related to Advaita Vedanta, which is a non-dualistic philosophy that holds that there is only one ultimate reality, and that all individual souls are ultimately one with this ultimate reality.