The new method of definition which Socrates applied to problems of human conduct was extended by Plato to the whole universe of the knowable.
Religion may " feel," like Tennyson's " man in wrath, " and may expatiate in an undefined awe; science alone is to possess the " knowable."
It appears, therefore, that Spencer ultimately describes the Knowable in terms of the mechanical conceptions of matter and motion, and that this must give a materialistic colouring to his philosophy.
Aristotle emphasized being as being, without always sufficiently asking whether the things whose existence he asserted are really knowable.
It may be urged in reply that the synthetic philosophy could be made consistent by transferring the knowable resistance and persistence of the unknowable noumenon to knowable phenomena on the one hand, and on the other hand by maintaining that all phenomena from the original nebula to the rise of consciousness are only ` 0 impressions produced on consciousness through any of the senses," after all.