因果关系的阶梯有三个梯级:观察、行动和想象。
The ladder of causation has three rungs: seeing, doing, and imagining.
煤炭不仅仅是一种商品,它是对美国未来的承诺。
精通不是天才或天赋的功能。它是时间和强烈专注于某一特定知识领域的功能。
To do mathematics is to explore an infinite landscape of ideas.
The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion.
理解过去对于塑造未来至关重要。