Separate the processes of creation from improving. You can’t write and edit， or sculpt and polish， or make and analyze at the same time. If you do， the editor stops the creator. While you invent， don’t select. While you sketch， don’t inspect. While you write the first draft， don’t reflect. At the start， the creator mind must be unleashed from judgement.

在数学中，提出问题的艺术必须比解决问题更有价值。

They just keep trotting back and forth across the bridge thinking there is something better on the other side. If they'd hang head down at the top of the thing and wait quietly, maybe something good would come along. But no—with men it's rush, rush, rush, every minute. I'm glad I'm a sedentary spider.

It seems to me that if you or I must choose between two courses of thought or action, we should remember our dying and try so to live that our death brings no pleasure to the world.