noun

deduction

dih-DUK-shun/dɪˈdʌkʃn/

Reasoning from general principles to a specific conclusion.

The detective uses deduction to identify a boot consistent with the print.

A detective compares a clearly matching muddy shoe print on the floor to the sole of a boot held beside it, then points toward the matching boot as the conclusion from evidence.

Etymology

deLatindown, away

+ductLatinlead

+ionLatinaction or result

From “leading down or away,” the underlying verb also meant “derive.” In logic, deduction became a derivation from a known principle, and hence the conclusion reached by that reasoning.

In context

The Way of Product Clips3:43

at the end he makes a deduction when he needs to like make an accusation as a consultant

Sherlock Holmes didn't do deduction, he did this instead...

More examples

All mammals breathe air, so deduction tells us that whales do too.
The proof relies on deduction from three basic assumptions.
Even careful deduction can yield a false conclusion from a false premise.

Forms

deduction · deductions

deduce verb — Reach a conclusion from general principles.

deductive adjective — Using general principles to reach specific conclusions.

Similar words

inference: Also includes conclusions that general principles do not guarantee.
reasoning: Covers thinking processes beyond deriving conclusions from general principles.