初学相对论时，正好见过彭加勒（Poincare）的小书《科学与假设》，那会儿能一口气把它读完，像八戒吃了人生果还不过瘾——有些观点一直影响着我，原来就是从彭老那儿听说的。例如，科学只有观察是不够的，科学需要事实，但事实的堆积绝不是科学。

The man of science must work with method. Science is built up of facts, as a house is built of stones; but an accumulation of facts is no more a science than a heap of stones is a house. Most important of all, the man of science must exhibit foresight. （第九章，Hypothesis in Physics）

第一句，还有的英译本是“the scientist must set in order”，即科学家要会“整理”，发现“有序”。最后一句更重要，科学家必须有远见，科学理论必须能预言。这个理所当然的观点，似乎并没有普及开来，我们很多同学还没有这样的自觉；他们认为，事实多了，自然会出现“规律”，仿佛砖块多了，房子就自然get into order了。

这会儿又看到这个小书，看到彭老接着举了Carlyle的例子，以前没有留意的：

Carlyle has written somewhere something after this fashion. "Nothing but facts are of importance. John Lackland passed by here. Here is something that is admirable. Here is a reality for which I would give all the theories in the world." Carlyle was a compatriot of Bacon, and, like him, he wished to proclaim his worship of the God of Things as they are.

John Lackland就是英国的约翰王（1199年即位），他几乎把英格兰在欧洲大陆的土地都丢了，所以赢得Lackland的绰号（法文名Jean Sans Terre，有个中译本没认出他来，直译为让桑泰尔）。在这里，彭老并不是直接引用卡莱尔的话，而是说老卡说过诸如此类的话（after this fashion，即like this）——内容大概来自他的Past and Future，但原文没有。这儿的意思大概说，老卡只关心事实，“崇拜”（他写过著名的《英雄与英雄崇拜》）事物本来面目（as they are）。

但是，老卡的老乡培根就不会那么说了：

But Bacon would not have said that. That is the language of the historian. The physicist would most likely have said: "John Lackland passed by here. It is all the same to me, for he will not pass this way again."

物理学家不关心那些“事实”，他们会说：王爷来过，但与我无关，因为他不会再来了。