This is a tough one because it is so close to the vice of “impetuosity.” But people who over-think things can be taking deliberation to the point of a vice, and some things in life (e.g. dancing with a partner, playing jazz) are much better with a practiced ability to improvise and take spontaneous initiative. Being able to strike while the iron is hot, to seize opportunity, are also things that call for spontaneity.

a.k.a. improvisation

Complementary virtues

Contrasting vices

Virtues possibly in tension

How to acquire or strengthen it

TBD

Notes and links

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Mentioned elsewhere

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Inspirational quotes

TBD