- Deductive: certain; conclusion does not go beyond the premises.
- Inductive: probable; conclusion extrapolates from premises.
- Abductive: optional; inference draws on best explanation from available choices.
- Reductive: reduced; shows absurdity of all other conclusions (“reductio ad absurdum”).
- Defeasible: practical; infers from convention and lack of complete background knowledge.
- Fallacious: wrongheaded; relies on informal and formal fallacies even if conclusion turns out true.