数学不是沿着一条清理得很好的高速公路小心行进，而是进入一个陌生的荒野的旅程，探险者常常会迷路。

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

The great powers are always searching for opportunities to gain power at the expense of their rivals, which makes them inherently aggressive.