We may thus conclude that virtue or excellence is a characteristic involving choice, and that it consists in observing the mean relative to us, a mean which is defined by a rational principle, such as a man of practical wisdom would use to determine it. It is the mean by reference to two vices: the one of excess and the other of deficiency. It is, moreover, a mean because some vices exceed and others fall short of what is required in emotion and in action, whereas virtue finds and chooses the median. Hence, in respect of its essence and definition of its essential nature virtue is a mean, but in regard to goodness and excellence it is an extreme.
Ethics, 335-322 B.C. [bold added].
What still strikes me most about the above quotation is that virtue is not a tepid, neither hot nor cold, state of being, but is rather a qualitative extreme. It is interesting to compare this Aristotelian notion with parts of the Gospel's teachings on morality, the Gospel which also presents virtue as a qualitative extreme, as in the Beatitudes.