Epicurus (341-270 BCE) was an ancient Greek philosopher who founded the school of philosophy known as Epicureanism. His teachings focused on the pursuit of happiness and the avoidance of unnecessary pain and suffering. Epicurus believed that pleasure, particularly mental pleasure, was the ultimate goal of life, and that moderation and the cultivation of friendships were key to achieving lasting happiness. He also advocated for the pursuit of knowledge to dispel irrational fears, such as the fear of death.