ended his lecture with a trite morality
morality
/mə-ˈra-lə-tē/
noun
a moral discourse, statement, or lesson
a literary or other imaginative work teaching a moral lesson
a doctrine or system of moral conduct
"Aesop's Fables" is famous as a morality.
noun
an allegorical play popular especially in the 15th and 16th centuries in which the characters personify abstract qualities or concepts (such as virtues, vices, or death)
something (such as a court trial) which involves a direct conflict between right and wrong or good and evil and from which a moral lesson may be drawn