Sherlock Holmes closed his eyes and placed his elbows upon the arms of his chair, with his finger-tips together.
歇洛克·福尔摩斯闭上了眼睛，两肘靠在椅子的扶手上，指尖合拢在一起，
"The ideal reasoner," he remarked, "would, when he had once been shown a single fact in all its bearings,
说道，“对于一个理想的推理家来说，一旦有人向他指明一个事实的一个方面以后，
deduce from it not only all the chain of events which led up to it but also all the results which would follow from it.
他就能从这一个方面不仅推断出导致这个事实的各个方面，而且能够推断出由此将会产生的一切后果。
As Cuvier could correctly describe a whole animal by the contemplation of a single bone,
正如居维叶，经过深思默想就能根据一块骨头准确地描绘出一头完整的动物一样。
so the observer who has thoroughly understood one link in a series of incidents
一个观察家，既已彻底了解一系列事件中的一环，
should be able to accurately state all the other ones, both before and after.
就应能正确地说明前前后后的所有其它的环节。
We have not yet grasped the results which the reason alone can attain to.
我们还没有掌握唯有理性才能获得的结果。
Problems may be solved in the study which have baffled all those who have sought a solution by the aid of their senses.
问题只有通过研究才能获得解决，企图凭借直觉解决问题的人是会失败的。

To carry the art, however, to its highest pitch,
不过，要使这种艺术达到登峰造极的地步，
it is necessary that the reasoner should be able to utilize all the facts which have come to his knowledge;
推理家就必须善于利用他已经掌握的所有事实，
and this in itself implies, as you will readily see, a possession of all knowledge,
这是你不难理解的，其本身就意味着要掌握一切知识。
which, even in these days of free education and encyclopaedias, is a somewhat rare accomplishment.
而要做到这一点，即使在有了免费教育和百科全书的今天，多少也还是一种难得的成就。
It is not so impossible, however, that a man should possess all knowledge which is likely to be useful to him in his work,
一个人要掌握对他工作可能有用的全部知识，倒也未必是绝对不可能的。
and this I have endeavoured in my case to do.
我本身就一直在作此努力。
If I remember rightly, you on one occasion, in the early days of our friendship, defined my limits in a very precise fashion."
如果我没记错的话，在我们结交之初，你曾有一次十分精确地指出了我的局限性。”