Democritus (Δημόκριτος) was a influential Ancient Greek philosopher, remembered today for his formulation of an atomic theory of the universe. Born in Thrace around 460 BCE, Democritus traveled extensively in his youth, engaging in a variety of philosophical and scientific studies.
He is often referred to as the "laughing philosopher" due to his emphasis on cheerfulness. Democritus believed that the purpose of life was happiness and saw this state as a form of tranquility free from fear and pain.