Measure what is measurable, and make measurable what is not so.
艺术家必须学会观察、感受和思考。
Every line we draw carries responsibility.
If you don’t like me, that’s your problem.
Loneliness is not lack of company, loneliness is lack of purpose.
在数学中,提出问题的艺术必须比解决问题更有价值。