The noumenon (/ˈnɒuːmᵻnɒn/) is a posited object or event that is known (if at all) without the use of ordinary sense-pe****tion. 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. Much of 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. In Kantian philosophy, the unknowable noumenon is often linked to the unknowable "thing-in-itself" (in Kant's German, Ding an sich), although how to characterize the nature of the relationship is a question yet open to some controversy.