DEMOCRITUS PLEASURE, HAPPINESS AND CHEERFULNESS Democritus of Abdera (second half of the 4th century BC) is known today primarily for his theory of atoms, which resembles to some extent modern scientific theories. In fact, he wrote many books about a variety of topics, including ethics, natural science, mathematics, music, and technical works. Only fragments of these works have survived, many of them quotations by Aristotle (who lived about two generations later). The following are Democritus’s main fragments on the topic of...