Full Idea
Every virtue is jealous of the others, and jealousy is a terrible thing. Even virtues can be destroyed through jealousy.
Gist of Idea
Virtues can destroy one another, through jealousy
Source
Friedrich Nietzsche (Thus Spake Zarathustra [1884], 1.07)
Book Reference
Nietzsche,Friedrich: 'Thus Spake Zarathustra', ed/tr. Hollingdale,R.J. [Penguin 1969], p.64
A Reaction
How much more subtle and plausible than the picture of accumulating virtues, like medals! Zarathustra says it is best to have just one virtue.