Duty, the most important subject in philosophy, I, 4; the most fruitful field, III, 5; the philosophic sects and duty, I, 4-6; best presentation, III, 7; classification, I, 7-9; order of importance, I, 58, 152-160; III, 90; to those who have wronged us, I, 33; to an enemy, I, 35-40; III, 98-115; to a slave, I, 41; III, 89; toward the laws, I, 148; of generosity, I, 42-60; of Temperance-Propriety, I, 100-151; III, 116-121; of Fortitude, III, 97-115; to be prosperous, II, 87; duties of youth, I, 122; II, 52; of age, I, 123; of magistrates, I, 124; of statesmen, I, 73-85; of private citizens, I, 124; of aliens, I, 125; _vs._ claims of friendship, III, 43-44; change of duty in change of circumstance, I, 31, 59; III, 32; "mean" and "absolute" duty, I, 8; III, 14; doubts as to, I, 147. Eloquence, at the bar, II, 66; its decline, II, 67; _see_ Oratory. Ennius, Quintus (239-169), a Greek by birth, the father of Roman poetry, wrote an epic (the Annals), I, 84; tragedies, I, 26, 51, 52; II, 23, 62; III, 62, 104; comedies and satires. Epaminondas, one of the greatest men of Greece, a student of Pythagorean philosophy, I, 155; the greatest general of Thebes, victorious at Leuctra (371), I, 84; humbled Sparta and made Thebes the leading city of Greece; fell at Mantinea (362). Epicurus (342-270), founded at Athens the school that bears his name; author of 300 books, natural and ethical philosophy; held happiness to be the highest good; Cicero confuses his teaching here with that of Aristippus and the Cyrenaics; with the latter, happiness consists in individual pleasures; with Epicurus, it is permanent calm of soul and freedom from pain, with pure and lasting pleasures--the pleasures that come from a life of righteousness, III, 12, 117; the gods existed but had nothing to do with human life, III, 102; adopted the atomic theory. His own life was temperate even to abstinence; his followers went to excess. A very popular school, III, 116; represented by Cicero as illogical, III, 39; their theory of society, I, 158. Epigoni, the sons of the Seven against Thebes; under Alcmaeon, Diomedes, etc., they conquered and destroyed the city. Subject of a tragedy of Accius, I, 114. Erillus, of Carthage, pupil of Zeno the Stoic, held that knowledge is the only good, while everything else is neither good nor evil; his ethical theories rejected, I, 6. Eteocles, son of Oedipus, drove out his brother Polynices, in order to reign alone, and brought on the war of the Seven against Thebes; the brothers fell by each other's hands; III, 82. Euripides (480-406), tragic poet of Athens; disciple of Anaxagoras and friend of Socrates; wrote 75 to 90 plays; 17 are extant; Cicero quotes from the _Hippolytus_, III, 82; the _Phoenissae_, III, 108.