"Healthy scepticism is the basis of all accurate observation."

"The more outré and grotesque an incident is the more carefully it deserves to be examined."

"One should always look for a possible alternative and provide against it. It is the first rule of successful planning."

"How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?"

"Crime is common. Logic is rare."