Chinese translation of a history professor's summary poem

At the end of Dr. James C Davis's The Human Story, a great overview of world history, he wrote a four-line poem that summarizes his positive view of the human history:

The world's still cruel,
That's understood.
But once was worse,
So far so good.

Here's a Chinese translation:

世界依然残酷，
世人无不了悟。
但它曾经更恶，
到如今还不错。

(My translation was first posted on weibo. My review of the book is on Goodreads.)