Do not do to others what angers you if done to you by others.
doquotes
To be is to do.
What am I to do here?
I obviously do everything to be “hard to understand” myself.
do / understand
The whole interest of my reason, whether speculative or practical, is concentrated in the three following questions: What can I know? What should I do? What may I hope?
To know what people really think, pay attention to what they do, rather than what they say.