By Descartes the principle was used as an instrument of scepticism, the beneficent scepticism of pulling down medieval philosophy to make room for modern science; by Berkeley it was used to combat the materialists; by Hume in the cause of scepticism once more against the intellectual dogmatists; by Kant to prepare a justification for a noumenal sphere to be apprehended by faith; by J.
It is upon this in the last resort that the distinction between the phenomenal world of our experience and a noumenal world beyond it is founded.
His First Principles, his book on metaphysics, is founded on this same point, that what we know is phenomena produced by an unknown noumenal power.
Thus it turns out that the objective agency, the noumenal power, the absolute force, declared unknown and unknowable, is known after all to exist, persist, resist and cause our subjective affections or phenomena, yet not to think or to will.
Lastly, when a theory of the world supposes a noumenal power, a resistent and persistent force, which results in an evolution, defined as an integration of matter and a dissipation of motion, which having resulted in inorganic nature and organic nature, further results without break in consciousness, reason, society and morals, then such a theory will be construed as materialistically as that of Haeckel by the reader, whatever the intention of the author.