Epicurus: His famous writing was Ethics He believed that nature is made up of atoms (compounds of atoms) developed by natural selection. The universe is unbounded; the soul is bound and distributed throughout the body and disintegrate at death. Epicurean ethics confused with the hedonism of Cyrenaic (believe that pleasure is the greatest good) The emphasized ethics are calm and tranquil life based on soul not the pleasure of the body. Happiness is based on the reduction of pain and fear of practical reasoning. Happiness is empirically identified with pleasure egoistic hedonism