Reasoning & Logic Vocabulary

a previous statement from which another is inferred

“The conclusion follows logically from the premise.”

Origin: Latin praemissa `things mentioned before` (from prae `before` + mittere `to send`)

a conclusion reached on the basis of evidence

“What inference can we draw from this data?”

Origin: Latin inferre `to bring in` (from in- `into` + ferre `to bear`)

the process of reasoning from general to specific

“Through deduction, we can rule out possibilities.”

Origin: Latin deductio `a leading down` (from deducere `to lead down`)

the process of reasoning from specific to general

“Induction from these cases suggests a pattern.”

Origin: Latin inductio `a leading in` (from inducere `to lead in`)

inference to the best explanation

“Abductive reasoning points to the most likely cause.”

Origin: Latin abductio `a leading away` (from abducere `to lead away`)

a form of reasoning with two premises and a conclusion

“The syllogism: all A are B, all B are C, therefore all A are C.”

Origin: Greek syllogismos `reasoning together` (from syn `together` + logizesthai `to reason`)

a proposition that follows from one already proven

“The corollary of this finding is significant.”

Origin: Latin corollarium `money for a garland, gratuity` (from corolla `small garland`)

a statement regarded as self-evidently true

“We'll take this as an axiom for our discussion.”

Origin: Greek axiōma `what is thought worthy` (from axios `worthy`)

a thing suggested or assumed as true as a basis

“Let's postulate that demand will remain stable.”

Origin: Latin postulare `to demand, request` (from poscere `to ask`)

a mistaken belief based on unsound reasoning

“That's a logical fallacy—correlation isn't causation.”

Origin: Latin fallacia `deception` (from fallere `to deceive`)

a conclusion that doesn't logically follow

“Your conclusion is a non sequitur from the evidence.”

Origin: Latin non sequitur `it does not follow` (from non `not` + sequi `to follow`)

a statement that is true by necessity; circular reasoning

“Saying 'it is what it is' is a tautology.”

Origin: Greek tautologia `repetition of what has been said` (from tauto `the same` + -logia `saying`)

a practical method for problem-solving

“Use this heuristic to quickly estimate the answer.”

Origin: Greek heuriskein `to find, discover` (related to eureka)

a process or set of rules for calculations

“The algorithm follows a specific logical sequence.”

Origin: Arabic al-Khwarizmi (from the name of mathematician Muhammad ibn Musa al-Khwarizmi)

a set of reasons justifying a course of action

“Explain the rationale behind your decision.”

Origin: Latin rationalis `of reason` (from ratio `reason, calculation`)

the relationship between cause and effect

“Establish causation, not just correlation.”

Origin: Latin causatio `excuse, pretext` (from causa `cause`)