Reasoning Patterns Vocabulary

reasoning from general premises to a logically certain conclusion

“Deduction guarantees truth if the premises are true.”

Origin: Latin deducere (to lead down from)

inferring general principles from specific observations

“Induction from past sunrises suggests tomorrow's sun will rise.”

Origin: Latin inducere (to lead into)

inferring the best explanation for observed evidence

“Abduction: the ground is wet, so it probably rained.”

Origin: Latin abducere (to lead away); term from C.S. Peirce

drawing conclusions based on similarities between cases

“Analogical reasoning from atoms to solar systems guided early physics.”

Origin: Greek analogia (proportion)

considering what would happen if something were different

“Counterfactual thinking: 'If I had left earlier, I wouldn't be late.'”

Origin: Latin contra (against) + factum (deed)

a sequence of reasoning steps leading to a conclusion

“The inference chain broke down at the third step.”

Origin: Latin inferre (to bring in) + English chain

if P then Q; P is true; therefore Q is true

“Modus ponens: if it rains, streets are wet; it rained; streets are wet.”

Origin: Latin 'method of affirming'

if P then Q; Q is false; therefore P is false

“Modus tollens: if it rained, streets are wet; streets are dry; it didn't rain.”

Origin: Latin 'method of denying'

a form of deductive reasoning with two premises and a conclusion

“All men are mortal; Socrates is a man; therefore Socrates is mortal.”

Origin: Greek syllogismos (reckoning together)

a mental shortcut that enables quick but imperfect judgments

“The availability heuristic judges frequency by ease of recall.”

Origin: Greek heuriskein (to find, discover)

accepting a good-enough option rather than seeking the optimal one

“Satisficing saves time when optimization costs exceed benefits.”

Origin: Portmanteau of satisfy + suffice; from Herbert Simon

if A relates to B and B relates to C, then A relates to C

“Transitivity: if A > B and B > C, then A > C.”

Origin: Latin transire (to go across)