ἀρετή

In case anyone forgot.

So I was bored and on Wikipedia, like always when I get a free moment and I stumbled upon an article on the german site about Duty and there was a special section on arete.
The thing I liked the best was a description by Otto Friedrich Bollnow, which explained arete as the swiftness of a horse or the sharpness of a knife. I like the -ness, for various (should be obvious by now) reasons.