形容世事变化无常，难以预测。

It is common sense to take a method and try it. If it fails, admit it frankly and try another. But above all, try something.

I don’t fear losing. I fear not giving my best.

最重要的胜利是在最艰难的失败之后取得的。

Liberal democracy may constitute the "end point of mankind's ideological evolution" and the "final form of human government."