Chapter 21
第21章
A Summary
总结
A short Summary of Chapters 1 to 20
有关文明起源的小结
Thus far, from the top of our high tower we have been looking eastward. But from this time on, the history of Egypt and Mesopotamia is going to grow less interesting and I must take you to study the western landscape.
以前我们站在历史的高度看到了很多世界的东部发生的故事。但是从这个时期起，埃及和米索不达米亚地区的历史将会变得不再那么重要和突出，我将要带你去研究以一下世界西部的风土人情。
Before we do this, let us stop a moment and make clear to ourselves what we have seen.
在我们做这件事之前，我们先暂停一下来弄清楚我们在过去的几章中都看到了什么。
First of all I showed you prehistoric man-a creature very simple in his habits and very unattractive in his manners. I told you how he was the most defenceless of the many animals that roamed through the early wilderness of the five continents, but being possessed of a larger and better brain, he managed to hold his own.
首先，我向你们展示了史前人类。史前人类是一种有着非常简单的生活习惯和枯燥的规矩的物种。我告诉了你这些在早期地球上生存的物种中最没有攻击力但是却拥有这更强大更聪明的大脑的史前人类是如何成功的把握住自己的命运的。
Then came the glaciers and the many centuries of cold weather, and life on this planet became so difficult that man was obliged to think three times as hard as ever before if he wished to survive.
然后来到了冰河世纪，那是好几个世纪的寒冷的天气，在这个星球上生活的物种的日子变得很难熬，于是他们如果想生存下来，必须花费比以前多两倍的脑力去想办法。
Since, however, that"wish to survive" was (and is) the mainspring which keeps every living being going full tilt to the last gasp of its breath, the brain of glacial man was set to work in all earnestness.
由于想活下来的念头已经成为他们主要而且特别强烈的念头，冰川时期的人类的大脑必须无休止的运转着，