Euthymia (philosophy)

Euthymia (Greek: ευθυμία, "gladness, good mood, serenity", literally "good thumos"). Democritus used this term in ancient philosophy to refer to one of the root aspects of human life's goal.

Diogenes Laertius records Democritus' position as "The chief good he asserts to be cheerfulness (euthymia); which, however, he does not consider the same as pleasure; as some people, who have misunderstood him, have fancied that he meant; but he understands by cheerfulness, a condition according to which the soul lives calmly and steadily, being disturbed by no fear, or superstition, or other passion."

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