Quotes About Logic

It is a capital mistake to theorize before you have all the evidence. It biases the judgment.

I assure you, my good Lestrade, that I have an excellent reason for everything that I do.

Then, how do you know?" "I see it, I deduce it. How do I know that you have been getting yourself very wet lately, and that you have a most clumsy and careless servant girl?" "My dear Holmes," said I, "this is too much. You would certainly have been burned, had you lived a few centuries ago.

I should have more faith. I ought to know by this time that when a fact appears to be opposed to a long train of deductions, it invariably proves to be capable of bearing some other interpretation.

Holmes," I cried, "this is impossible." "Admirable!" he said. "A most illuminating remark. It IS impossible as I state it, and therefore I must in some respect have stated it wrong.

To the logician all things should be seen exactly as they are, and to underestimate one's self is as much a departure from truth as to exaggerate one's own powers. When I say, therefore, that Mycroft has better powers of observation than I, you may take it that I am speaking the exact and literal truth.

No, no: I never guess. It is a shocking habit—destructive to the logical faculty.

Science of Deduction

Holmes," I cried, "this is impossible." "Admirable!" he said. "A most illuminating remark. It IS impossible as I state it, and therefore I must in some respect have stated it wrong. Yet you saw for yourself. Can you suggest any fallacy?

There are fifty who can reason synthetically for one who can reason analytically.

It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (p. 261).

His conclusions were as infallible as so many propositions of Euclid. So startling would his results appear to the uninitiated that until they learned the processes by which he had arrived at them they might well consider him as a necromancer.

A mistake would have been fatal. -Sherlock Holmes-

There are instincts which are deeper than reason. — Arthur Conan Doyle, from "The Nightmare Room," Collected Works of Sir Arthur Conan Doyle . (Delphi Classics; 6 edition May 13, 2011)

Eliminate the impossible, and what ever remains, however improbable, must be the truth - Sherlock Holmes

It is a capital mistake to theorize in advance of the facts.

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

I have already explained to you that what is out of the common is usually a guide rather than a hindrance.In solving a problem of this sort, the grand thing is to be able to reason backward. 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.

Pero el amor es una cosa emocional y todo lo que es emocional se opone a ese frío razonamiento que me parece la cualidad más importante del hombre y que antepongo a lo demás

Detection is, or ought to be, an exact science, and should be treated in the same cold and unemotional manner.

Eliminato l'impossibile ció che resta, per improbabile che sia, deve essere la veritá

But there was something in the ice-cold reasoning of Holmes which made it impossible to shrink from any adventure which he might recommend. One knew that thus, and only thus, could a solution be found. I clasped his hand in silence, and the die was cast.

Arthur Conan Doyle

I have no data yet. 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. But the note itself. What do you deduce from it?