Final answer:
According to Aristotle, ethical behavior is described as the 'golden mean,' which is the balanced midpoint between excessive and deficient behaviors, contributing to an individual's eudaimonia or flourishing.
Step-by-step explanation:
According to Aristotle, the term that describes ethical behavior as a midpoint between extremes is known as the golden mean. Aristotle's ethical philosophy, as outlined in Nicomachean Ethics, proposes that virtue is the mean between a deficiency and an excess, which is both an application of practical wisdom and a balance between insufficient and excessive behaviors. He provides the example of bravery, where true courage is seen as the balanced point between cowardice and rashness. In this way, Aristotle establishes the concept of virtue ethics, where the virtuous action is one that strikes a harmonious balance, contributing to a person's eudaimonia or flourishing life.