Arthur Conan Doyle Quotes

We may either proceed from principles to facts, or recede from facts to principles.

The ideal reasoner, he remarked, would, when he had once been shown a single fact in all its bearings, 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.

Causal analysis provides absolutely no value judgment, and a value judgment is absolutely not a causal explanation.

The inquiries of the jurist are in truth prosecuted much as inquiry in physic and physiology was prosecuted before observation had taken the place of assumption.

Logic teaches rules for presentation, not thinking.

A great book seeks to explain causality, not correlation. It works to point out the circumstances in which it works, and where it doesn't. And in so doing, it is broadly applicable.

The proper method for inquiring after the properties of things is to deduce them from experiments.

I am always fascinated by the structure of things; why do things work this way and not that way.

You should carefully study the Art of Reasoning, as it is what most people are very deficient in, and I know few things more disagreeable than to argue, or even converse with a man who has no idea of inductive and deductive philosophy.

You must acquire something of that industrious habit of mind which the study of natural science gives,—the art of comparing, of perceiving true likenesses and true differences, and so of classifying and arranging what you see; the art of connecting facts together in your mind in cause and effect

Logic can become enormously difficult, and it would undoubtedly be well to produce more assurance in its use.

It is generally believed that our science is empirical and that we draw our concepts and our mathematical constructs from the empirical data. If this were the whole truth, we should, when entering into a new field, introduce only such quantities as can directly be observed, and formulate natural laws only by means of these quantities.

Every fundamental law has exceptions. But you still need the law or else all you have is observations that don't make sense. And that's not science. That's just taking notes.

Logic takes care of itself; all we have to do is to look and see how it does it.

Logic is not a body of doctrine, but a mirror-image of the world. Logic is transcendental.

It is very difficult for us to assess intent, so we have to work back from actions.

One of the most admirable things about history is, that almost as a rule we get as much information out of what it does not say as we get out of what it does say.… history consists of two equal parts; one of these halves is statements of fact, the other half is inference, drawn from the facts. To the experienced student of history there are no difficulties about this; to him the half which is unwritten is as clearly and surely visible, by the help of scientific inference, as if it flashed and flamed in letters of fire before his eyes. When the practiced eye of the simple peasant sees the half of a frog projecting above the water, he unerringly infers the half of the frog which he does not see. To the expert student in our great science, history is a frog; half of it is submerged, but he knows it is there, and he knows the shape of it.

There are three principal means of acquiring knowledge available to us: observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination.

The true man of science - will smell, taste, see, hear better than other men.

Sometimes I implant thoughts, sometimes I extract thoughts, but I don't like to explain it too much. It's based on science, deduction, and reasoning - it's a bit like what 'Sherlock' does, except that's a dramatised version. I look at every clue around me.

The most successful detectives owe their success to noticing small signs. Scouts are natural detectives and never let the smallest detail escape them. These small things are called by Scouts 'Sign.'

The truth is, as you know, people like us look at what's happening in the world, and then we project it forward. We think, 'If I know A and B, then I've got to know that C and D are coming,' and that's kind of the way it's been with my fiction.

Attention to detail - Sherlock certainly has that, and my memory is pretty good - but not as good as his.

Sometimes we look at patterns, and we look at things that are happening, and sometimes you can't dismiss everything as a conspiracy.

Intelligence is an extremely subtle concept. It's a kind of understanding that flourishes if it's combined with a good memory, but exists anyway even in the absence of good memory. It's the ability to draw consequences from causes, to make correct inferences, to foresee what might be the result, to work out logical problems, to be reasonable, rational, to have the ability to understand the solution from perhaps insufficient information. You know when a person is intelligent, but you can be easily fooled if you are not yourself intelligent.