How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?
To quote Sir Arthur Conan Doyle, author of famous Sherlock Holmes stories published between 1887 and 1927:
"in solving a problem of this sort, the grand thing is to be able to reason backwards. That is a very useful accomplishment, and a very easy one, but people do not practise it much. In the everyday affairs of life it is more useful to reason forward, and so the other comes to be neglected. There are fifty who can reason synthetically for one who can reason analytically."