What other dungeon is so dark as one's own heart! What jailer so inexorable as one's self!

可以说，消化道是生命物质最初和最古老的实验室。

The essence of mathematics lies in its freedom.

每本小说都是一次未知的旅程，即使对写它的人来说也是如此。

The first step in the art of cutting metals is to find a man who has the necessary skill and experience.

光是建筑中最重要的材料。