Final answer:
Aristotle believed that a truly happy man must cultivate virtues to achieve eudaimonia or flourishing. Virtues are habits of character that aid in making preferable choices. By developing virtues through practice, individuals can lead a fulfilling life and attain true happiness.
Step-by-step explanation:
Aristotle believed that a truly happy man must cultivate virtues in order to achieve eudaimonia, which can be understood as flourishing or leading a fulfilling life. According to Aristotle, virtues are habits of character that help us make preferable choices in different situations. By developing virtues through practice and habituation, individuals can live a good life and attain true happiness.