Final answer:
Aristotle's doctrine of the mean does not apply to acts which are inherently wrong, such as an act of adultery, because such acts do not have a mean balance between excess and deficiency.
Step-by-step explanation:
According to Aristotle, the doctrine of the mean suggests that virtue is the mean between a deficiency and excess of a trait or behavior. This concept does not apply to all situations. Specifically, it does not apply to acts which are by nature always wrong, such as an act of adultery.
For Aristotle, virtues involve finding balance and moderation in one's actions, a quality which contributes to eudaimonia, or flourishing and well-being. However, some acts, like adultery, are not subject to this doctrine because they are considered wrong in themselves and do not have a mean.