1、It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories， instead of theories to suit facts.
2、在这个世界上，你到底做了些什么，这到无关紧要。重要的是，你如何使别人相信你做了些什么。(血字的研究)
3、I never guess. It is a shocking habit – destructive to the logical faculty."
4、没有比平凡的事物更不寻常，更值得研究的了。(身份案)
5、我从不猜测，那是破坏思维能力的坏习惯。(四签名)
6、越是稀奇古怪的东西，通常包含隐密的成分越少。(红发会)
7、I never make exceptions. An exception disproves the rule.
8、如果能保证毁灭你，那么，为了社会的利益，即使和你同归于尽，我也心甘情愿。(最后一案)
9、In solving a problem of this sort， the grand thing is to be able to reason backward.
10、One should always look for a possible alternative， and provide against it. It is the first rule of criminal investigation.
11、There is nothing more deceptive than an obvious fact.
12、我从不假设例外，例外会打破调查的原则。(or我向来不作任何例外，定律没有例外。)(四签名)
13、犯罪调查的第一法则是：你必须寻找各种可能解释事情的方法，然后想办法看看能否试图推翻它。(黑彼得)
14、犯罪是普遍的，而逻辑是难得的东西。因此，你详细记述的应该是逻辑而不是罪行。(桐山毛榉案)
15、You see， but you do not observe. The distinction is clear.
16、将异常的东西和神秘混淆起来是十分错误的。(血字的研究)
17、If you precise destruction， in the public interest， I am willing to accept death.
18、Any truth is better than indefinite doubt.
19、It is a mistake to confound strangeness with mystery.
20、What you do in this world is a matter of no consequence. The question is， what can you make people believe that you have done.
21、在解决这类问题时，先前假定的观点必须能够向前回溯成立。(血字的研究)
22、There is nothing so unnatural as the commonplace.
23、When you have eliminated the impossible， whatever remains， however improbable， must be the truth.
24、The more bizarre a thing is， the less mysterious it proves to be.
25、任何确实得到的事实都要强于不确定的猜测。(黄面人)
26、排除一切不可能的，剩下的即使再不可能，那也是真相。(四签名)
27、你是在看，而不是在观察。两者的区别很明显。(波希米亚丑闻)
28、Crime is common. Logic is rare. Therefore， it is upon the logic rather than upon the crime
29、没有什么比一个显而易见的事实更能迷惑人了。(博斯科姆比溪谷秘案)