昨晚看《飞碟探索》，看到一篇关于阿波罗13号的文章，胖鹿感慨说这么多年了，人类的航天科技似乎停滞不前了几十年。的确，前苏联解体后，美国也失去了在航天领域投入巨额资金的动力。毕竟太空技术是烧钱的买卖，不是一般国家玩得起的。
本该只属于科学领域的航天科技随着意识形态两大阵营的消融而荒废，不能不说也是人类狭隘的一个表现。回望历史，很多科技的进步居然真的都是被冲突和战争催生的，坦克、高速公路、原子弹、人造卫星、登月计划......甚至现代医学上用的麻醉剂、可卡因最初都是战场上的军医发明的。
敌人不存在了，自己就不必继续发展了。这有点像一个去少林寺学了十年武功的少年终于有天下山去为父报仇，却发现仇人早死了。空有这一身功夫，却哪里去用呢？正是“我要这铁棒有何用”般的空虚。
人类的愚蠢常常就表现在这种争斗上，几千年的历史中，人类几乎从未发生过心无芥蒂齐心协力共同完成什么壮举的合作，并且这种彼此间的敌视和防备还将永无止境地存在下去。
人性啊。
英国哲学家托马斯-霍布斯和约翰-洛克对人性中普遍存在的安全困境（security dilemma)有过系统的研究和阐述。
霍布斯在《利维坦》中famously argued, "The life without rule of law is the life of every man against every man."人人与人人为敌，就是人类“囚徒困境”(prisoners' dilemma)的必然宿命。
可悲的人类。
想起大学时代学过的一首美国诗歌"Mending Wall", by Robert Frost.
我上大三时，有一门课叫”英美诗歌散文欣赏“，教我们的是一位美国老师。欣赏过的几十首诗歌散文中我只对佛洛斯特的这首诗印象深刻。
佛洛斯特的这首诗在美国文学史上地位极高，几乎是所有美国文学课都无法绕开的一个里程碑。
诗人讲了一件生活中的小事：
自己家和隔壁邻居家之间的篱笆墙坏了。诗人觉得没必要修补，因为两家都没养什么家畜，不会出现鸡鸭跑到邻居家造成困扰。诗人家院里种有苹果树，邻居家院子里只有一棵松树。既然这样，两家都不用担心自己的果实被混淆或造成其他麻烦。于是诗人试图去劝说邻居不要费劲修那扇篱笆墙了。邻居不同意，坚持认为“Good fences make good neighbors"（有堵好墙才能作好邻居）。
诗人在这件小事里深深感到了人与人之间根深蒂固的隔膜与距离，颇有“世上本没有篱笆墙，有了邻居才建起了墙”之类的感慨。（引号里这句是我演绎的）
美国老师解释这首诗为什么好，说"Mending Wall" deals with the distances and tensions between men. The poem explores the contradictions in life and humanity, including the contradictions within each person, as man "makes boundaries and he breaks boundaries".
全诗如下：
Mending Wall
By Robert Frost
Something there is that doesn't love a wall,
That sends the frozen-ground-swell under it,
And spills the upper boulders in the sun;
And makes gaps even two can pass abreast.
The work of hunters is another thing:
I have come after them and made repair
Where they have left not one stone on a stone,
But they would have the rabbit out of hiding,
To please the yelping dogs. The gaps I mean,
No one has seen them made or heard them made,
But at spring mending-time we find them there.
I let my neighbour know beyond the hill;
And on a day we meet to walk the line
And set the wall between us once again.
We keep the wall between us as we go.
To each the boulders that have fallen to each.
And some are loaves and some so nearly balls
We have to use a spell to make them balance:
"Stay where you are until our backs are turned!"
We wear our fingers rough with handling them.
Oh, just another kind of out-door game,
One on a side. It comes to little more:
There where it is we do not need the wall:
He is all pine and I am apple orchard.
My apple trees will never get across
And eat the cones under his pines, I tell him.
He only says, "Good fences make good neighbours."
Spring is the mischief in me, and I wonder
If I could put a notion in his head:
"Why do they make good neighbours? Isn't it
Where there are cows? But here there are no cows.
Before I built a wall I'd ask to know
What I was walling in or walling out,
And to whom I was like to give offence.
Something there is that doesn't love a wall,
That wants it down." I could say "Elves" to him,
But it's not elves exactly, and I'd rather
He said it for himself. I see him there
Bringing a stone grasped firmly by the top
In each hand, like an old-stone savage armed.
He moves in darkness as it seems to me,
Not of woods only and the shade of trees.
He will not go behind his father's saying,
And he likes having thought of it so well
He says again, "Good fences make good neighbours."
我们内心里的那堵墙何止是篱笆墙？又何曾有人想过要修葺过？即便想，能吗？
世上最可恨的东西大概就是墙了。
By the way, did you know美国还真的有一个Mending Wall Day呢。是一个网站推出的社区公益活动（https://americanstonecraft.com/）.每年设定一天为“修墙日”，鼓励人们在这天共同出力修葺和美化社区的石头墙。
网站上有段介绍：Mending Wall Day is an annual event started in 2015 by our team here at American Stonecraft. Our goal with Mending Wall Day is to increase cultural awareness of stonewalls by organizing independent community gatherings where neighbors and community members convene to rebuild and tend to fieldstone walls in visible public settings.
人心里有修不好的墙，国与国之间有推不倒的墙。有些墙该修，而有些墙合该被推倒。我更愿意相信，at the end of the day, 所有柏林墙都会像雷峰塔一样倒掉。