According to Aristotle, deriving pleasure from a virtuous act is a sign that you have acquired that virtue.
Who was Aristotle?
Aristotle, Greek Aristotle, (born 384 BC, Stagira, Chalcidice, Greece - died 322, Chalcis, Euboia), ancient Greek philosopher and scientist, one of the greatest intellectual figures of Western history.
He was the author of a philosophical and scientific system that became the framework and medium of both Christian scholasticism and medieval Islamic philosophy.
Even after the intellectual revolutions of the Renaissance, Reformation, and Enlightenment, Aristotelian concepts remained embedded in Western thought.