For Epicurus, the purpose of philosophy was to attain the happy, tranquil life, characterized by ataraxia, peace and freedom from fear, and "aponia", the absence of pain, and by living a self-sufficient life surrounded by friends. He taught that pleasure and pain are the measures of what is good and bad, that death is the end of the body and the soul and should therefore not be feared, that the gods do not reward or punish humans, that the universe is infinite and eternal, and that events in the world are ultimately based on the motions and interactions of atoms moving in empty space.