Epicurus was an ancient Greek philosopher who founded the school of philosophy known as Epicureanism. He taught that the purpose of life is to attain happiness through the pursuit of pleasure and the avoidance of pain. His philosophy emphasized the importance of friendship, moderation, and the pursuit of knowledge as pathways to a tranquil life. Epicurus believed that understanding the natural world and the limits of desires could lead to a more fulfilling existence. He argued that fear of the gods and death were the main sources of human anxiety, and by overcoming these fears, individuals could achieve true happiness and peace of mind.