Matter exists eternally and is all there is. God does not exist. The cosmos exists as a uniformity of cause and effect in a closed system. Death is extinction of personality and individuality. History is a linear stream of events linked by cause and effect without an overarching purpose.
Ethics is related only to human beings.
Marxism The Persistence of Naturalism 5. Existentialism Basic Atheistic Existentialism 1. Each person is totally free as regards their nature and destiny. The highly wrought and tightly organized objective world stands over against human beings and appears absurd. In full recognition of and against the absurdity of the objective world, the authentic person must revolt and create value.