Agnosticism is a theory of the Unknowable which assumes its most definite form in the denial of the possibility of any knowledge of God. 1st kind: connected with theory that we know only the phenomenal and a logical deduction from it. 2d kind: held by those who do not hold the phenomenal theory of knowledge but rest their deduction that the Infinite and the Absolute are unknowable on the limitation of human intelligence, maintaining that the infinite transcends the limits of our knowledge, and must on that account remain unknown, while the existence of the infinite God must be a matter of belief.