Abduction (inference to the best explanation)

Inferring that a hypothesis is probably true because it would best explain the evidence in front of you.

Also: abduction, inference to the best explanation, IBE, abductive reasoning, retroduction

What it means

Abduction reasons from evidence to the explanation that would best account for it. Seeing breadcrumbs, a plate and jam on the kitchen table, you conclude that a housemate had a midnight snack. Astronomers inferred an unseen planet, Neptune, to explain irregularities in the orbit of Uranus. Charles Sanders Peirce introduced the term, chiefly for the step of forming a new hypothesis; today it usually means justifying a belief by its explanatory power, a view defended at length by Peter Lipton. Unlike deduction, the conclusion can be overturned by further evidence. Critics such as Bas van Fraassen warn that the best explanation we have thought of may only be "the best of a bad lot".

The questions it belongs to

• 6.8.1 Scientific ExplanationWhen have you explained something, rather than just described it?
• 2.2 Sources of KnowledgeWhich ways of finding things out actually work?

Thinkers

• Charles Sanders Peirce
• Gilbert Harman
• Peter Lipton
• Bas van Fraassen

Traditions

• American
• Analytic

To read

• The Fixation of Belief and How to Make Our Ideas Clear — Charles Sanders Peirce

Sources and further reading

• Abduction (Stanford Encyclopedia of Philosophy)
• Peirce's Logic (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 Not peer-reviewed.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.

All terms in the glossary