Full Idea
If the mean between prodigality and avarice is supposed to be one of degree, then one vice would pass over into the opposite vice only through the virtue. So virtue would simply be a diminished, or rather a vanishing vice.
Gist of Idea
If virtue is the mean between vices, then virtue is just the vanishing of vice
Source
Immanuel Kant (Metaphysics of Morals II:Doctrine of Virtue [1797], 432 I.I)
Book Reference
Kant,Immanuel: 'The Metaphysics of Morals', ed/tr. Gregor,Mary [CUP 1991], p.228
A Reaction
Interesting, but not convincing. Doesn't the thought equally show that vice is a vanishing virtue? Aristotle gives the example of the quantity of food we eat, which obviously passes from starvation to appropriate diet to gluttony.
Related Idea
Idea 60 The mean is relative to the individual (diet, for example) [Aristotle]