Full Idea
How can we learn self-knowledge? Never by taking thought, but rather by action. Try to do your duty and you'll soon discover what you're like.
Gist of Idea
We gain self-knowledge through action, not thought - especially when doing our duty
Source
Wolfgang von Goethe (Maxims and Reflections [1825], 442)
Book Reference
Goethe,J. Wolfgang: 'Maxims and Reflections' [Penguin 1840], p.57
A Reaction
Good! I even like the unfashionable bit about duty. If you just do what you want, you will discover your interests, but not so much about your capacities. However, when you have to do something less comfortable, it is very revealing.