Ataraxia

Ataraxia is a lucid state of robust equanimity and imperturbability, characterized by a profound freedom from mental and emotional distress, anxiety, or worry. 

Philosophical Origins

The term stems from Ancient Greek (a- meaning "without" and tarasso meaning "to disturb") and was a major goal in several Hellenistic philosophies: 

Epicureanism: Epicurus believed that removing fear, eliminating unnecessary desires, and avoiding pain was the ultimate path to achieving ataraxia and true happiness. 

Stoicism: Stoics believed in achieving this tranquility of mind by mastering one's emotions, practicing self-discipline, and strictly focusing on what is within personal control. 

Pyrrhonism & Skepticism: Skeptics pursued this state by suspending judgment about non-evident matters, which they found eliminated mental agitation. 

Modern Application

While rooted in antiquity, the concept closely parallels modern psychological ideas of mindfulness, emotional autonomy, and distress tolerance. In the subreddit dedicated to exploring Stoicism, users generally agree that reaching a state of ataraxia requires active practice in radical acceptance of external events and a focus on one's own internal virtues and reactions. It is frequently referenced in literature and psychology as a description for deep, enduring inner peace.