The Magna Moralia (or "Great Ethics") is a treatise on ethics traditionally attributed to Aristotle, though the consensus now is that it represents an epitome of his ethical thought by a later, if sympathetic, writer. Several scholars have disagreed with this, taking the Magna Moralia to be an authentic work by Aristotle, notably Friedrich Schleiermacher, Hans von Arnim, and J. L. Ackrill. In any case, it is considered a less mature piece than Aristotle's other ethical works, viz. the Nicomachean Ethics, the Eudemian Ethics, and Virtues and Vices. There is some debate as to whether they follow more closely the Eudemian or the Nicomachean version of the Ethics.
The name "Magna Moralia" cannot be traced further back in time than the reign of Marcus Aurelius. Prof. Henry Jackson suggested that the work acquired its name from the fact that the two rolls into which it is divided would have loomed large on the shelf in comparison to the eight rolls of the Eudemian Ethics, even though the latter are twice as long.
Saint Gregory's Commentary on Job is sometimes also referred to by the title Magna Moralia.