In the case of Sherlock Holmes, deductive reasoning was his ability to investigate and then eliminate different hypotheses to eventually find the correct one and solve the case.

University of Michigan - Ann Arbor

Eliminating different hypothesis to draw a conclusion.  The conclusion logically follows from "premises".

Deductive reasoning

Pearl, J., & Mackenzie, D. (2018). $\mathit{The \ Book \ of \ Why: \ The \ New \ Science \ of \ Cause \ and \ Effect.}$ Basic Books.

The Book of Why

Both Induction and Deduction are necessary within casual inference because they are two ways of approaching a problem and often go hand in hand. Induction goes from evidence -> hypothesis while deduction works in the forward direction; cause (hypothesis) -> effect (theory, conclusion). Artificial Intelligence has started automating Induction and Deduction, an example is Bayesian networks. 

Stages of Casual Inference: Induction and Deduction

Sherlock Holmes' use of deductive reasoning

Consists of premises followed by a conclusions.

Syllogism

People apply mental models using their imagination to solve deductive reasoning problems. The mental model is the representation of a situation in someones mind and can help determine validity of syllogisms.

Mental model approach

In order to test a rule it is necessary to look to falsify the rule. The canonical problem experiment that shows this is the Wason four-card problem, where students are asked to test the validity of a rule given four cards and must try to turn over cards to confirm and falsify the rule to determine if its valid.

Learn Before

Related