An empire founded by war has to maintain itself by war.

数学的本质在于其自由性。

Economic history teaches us that change is possible, but it is rarely easy.

解释：既要追悔以往的过失，也要预防将来可能发生的错误。

数学的美在于它揭示隐藏的对称性和真理的能力。

We are all haunted by the ghosts of our own making.

"In the end, we are all just stories. What matters is how we tell them."

火药不仅是破坏的工具，它也能成为创造的媒介。