Deduction

Look at the big picture of a situation and infer from that what some fine details must have been. Anthropologists look at the bones of a dinosaur and deduce what it must have eaten, in spite of the fact that there are no clues in the fossils themselves. The teeth, the claws, the posture and provide clues to some other fact that cannot be measured directly. They arrive at their understanding of the dietary habits by deduction.

The most famous “deducer” was probably Sherlock Holmes, legendary thinker, but not a real person. “Elementary my dear Watson” is a statement know by millions and its meaning is understood. Arthur Conan Doyle created a character with prodigious powers of thought. He had built a person store of knowledge that was vast and eclectic. This he applied to crime scenes and people to deduce facts that others could not perceive.

In an earlier post I discussed the need for induction because people experience the world in small pieces that they must draw meaning from. Like Holmes, this information becomes the knowledge from which deduction can take place. It seems to be a cycle of thought that begins with perception and is followed by induction. The knowledge built by these is then available for deduction on later problems.

Deduction is a higher form of thought. It is not directed by a set of immediately perceived information. Instead, the deducer must select for himself what knowledge is applicable in the process of deducing specifics from a general observation, thought, or theory. This would imply that deduction is open to many more avenues of approach. Deduction can be driven by the historical experience and accumulation of the person doing it. Induction is more reactive to the immediate perception and is more likely to proceed along a similar path for all individuals. Because deduction can follow so many different paths, it should be a technique that leads to many more different inquiries, discoveries, and mistakes than does induction.

In a Sherlock Holmes story, he, Watson, and Inspector Lestrade all arrive at different conclusion when presented with similar evidence. In the stories this is because Holmes is brilliant, Watson is practical, and Lestrade is a dullard. In practice this should be driven much more by the knowledge available to each and the disciplined techniques that each has developed to apply that knowledge. Perhaps Holmes was the fictional equivalent of Einstein and the power of his mind far surpassed that of any others in police work. But, the brain falls under the normal distribution. Most of us are equipped with nearly the same brainpower. We have similar raw capabilities and can each conquer similar problems. The differences in our line of thought are probably due more to the knowledge we have stocked up and a certain amount of luck in sifting and organizing that knowledge. The power of the individual brain is much like that of its neighbors.