Induction

Reasoning from observed cases to unobserved ones or to general laws, giving conclusions that are probable rather than guaranteed.

Also: inductive reasoning, inductive inference, problem of induction

What it means

Inductive reasoning moves from what has been observed to what has not: every spider examined so far has eight legs, so all spiders probably do. Unlike valid deduction, its premises can be true while its conclusion is false, so inductive arguments are judged as strong or weak, and new evidence can strengthen or weaken them. David Hume asked what justifies such inferences. Deduction cannot, because nature could change without contradiction, and appealing to past success assumes the future will resemble the past, which is circular. Hume concluded that habit, not reason, drives induction. Later responses include Bayesian probability, Hans Reichenbach's pragmatic vindication, and Nelson Goodman's 'new riddle', which asks why we project some predicates rather than others.

The questions it belongs to

• 2.2 Sources of KnowledgeWhich ways of finding things out actually work?
• 6.8 Philosophy of ScienceWhat makes a claim scientific?

Thinkers

• David Hume
• Nelson Goodman
• Hans Reichenbach

Traditions

• Modern European
• Analytic

To read

• A Treatise of Human Nature — David Hume
• An Enquiry Concerning Human Understanding — David Hume
• An Enquiry Concerning the Principles of Morals — David Hume

Sources and further reading

• The Problem of Induction (Stanford Encyclopedia of Philosophy)
• Deductive and Inductive Arguments (Internet Encyclopedia of Philosophy)

Written by the Coordinates of Thought editors and checked against the sources above on 29 October 2026. Not peer-reviewed. How we write and check.

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