(philosophy) In the philosophy of Immanuel Kant (1724-1804) and those whom he influenced, a thing as it is independent of any conceptualization or perception by the human mind; a thing-in-itself, postulated by practical reason but existing in a condition which is in principle unknowable and unexperienceable.
The noumenon (/ˈnɒuːmᵻnɒn/, from Greek: [εν]νοούμενον) is a posited object or event that exists without sense or perception.1 The term noumenon is generally used in contrast with or in relation to phenomenon, which refers to anything that can be apprehended by or is an object of the senses. Modern philosophy has generally been skeptical of the possibility of knowledge independent of the senses, and Immanuel Kant gave this point of view its canonical expression: that the noumenal world may exist, but it is completely unknowable through human sensation.
Is that just a euphemism to shield claims that cannot be established using methods of
methodological naturalism, which is a scientific standard?