Spencer is careful to insist upon this relation of the phenomenal to the noumenal.
The phenomenal is a mode of the noumenal, as heat is a mode of motion.
This will at once be recognised as holding of the noumenal conditions of the given manifold.
Sensations, Kant holds, have a twofold origin, noumenal and mechanical.
Comte was never willing to face the fact that the very existence of knowledge has a noumenal as well as a phenomenal side.
Further, we have no right to conceive them as the activities of a noumenal self.
But with the rejection of Kant's noumenal world, the critical method assumed a different import.
It may be that in the noumenal sphere all partial realities are conditioned by an unconditioned whole.
(So are all phenomenal bodies but reflections of the noumenal).
These last are events in time, and are effects not of noumenal but of mechanical causes.