Greek a without; theos, God

Denial of God’s existence; system opposed to deism or theism, maintaining the existence of God and of one God only; in its extremist form, the denial of the existence of a First Cause; in less extreme, the substitution of matter, external and self-subsistent, for a God spiritual and personal; often confused with agnosticism and pantheism. Moral atheism comprises those ethical systems which teach that the morality of human acts has no reference to a Divine law-giver, i.e., godlessness in conduct regardless of a system of morals or of religious faith.