[ree-zuh-ning, reez-ning]


the act or process of a person who reasons.
the process of forming conclusions, judgments, or inferences from facts or premises.
the reasons, arguments, proofs, etc., resulting from this process.

Origin of reasoning

First recorded in 1325–75, reasoning is from the Middle English word resoninge. See reason, -ing2
Related formsrea·son·ing·ly, adverbhalf-rea·son·ing, adjectivenon·rea·son·ing, adjective




a basis or cause, as for some belief, action, fact, event, etc.: the reason for declaring war.
a statement presented in justification or explanation of a belief or action: I dare you to give me one good reason for quitting school!
the mental powers concerned with forming conclusions, judgments, or inferences: Effective leadership requires a person of reason.
sound judgment; good sense.
normal or sound powers of mind; sanity.
Logic. a premise of an argument.
  1. the faculty or power of acquiring intellectual knowledge, either by direct understanding of first principles or by argument.
  2. the power of intelligent and dispassionate thought, or of conduct influenced by such thought.
  3. Kantianism.the faculty by which the ideas of pure reason are created.

verb (used without object)

to think or argue in a logical manner.
to form conclusions, judgments, or inferences from facts or premises.
to urge reasons which should determine belief or action.

verb (used with object)

to think through logically, as a problem (often followed by out).
to conclude or infer.
to convince, persuade, etc., by reasoning.
to support with reasons.

Origin of reason

1175–1225; Middle English resoun, reisun (noun) < Old French reisun, reson < Latin ratiōn- (stem of ratiō) ratio
Related formsrea·son·er, nounnon·rea·son, nounnon·rea·son·er, nounout·rea·son, verb (used with object)sub·rea·son, noun

Synonyms for reason

Synonym study

1. Reason, cause, motive are terms for a circumstance (or circumstances) which brings about or explains certain results. A reason is an explanation of a situation or circumstance which made certain results seem possible or appropriate: The reason for the robbery was the victim's display of his money. The cause is the way in which the circumstances produce the effect, that is, make a specific action seem necessary or desirable: The cause was the robber's extreme need of money. A motive is the hope, desire, or other force which starts the action (or an action) in an attempt to produce specific results: The motive was to get money to buy food for his family.

Usage note

The construction reason is because is criticized in a number of usage guides: The reason for the long delays was because the costs greatly exceeded the original estimates. One objection to this construction is based on its redundancy: the word because (literally, by cause ) contains within it the meaning of reason; thus saying the reason is because is like saying “The cause is by cause,” which would never be said. A second objection is based on the claim that because can introduce only adverbial clauses and that reason is requires completion by a noun clause. Critics would substitute that for because in the offending construction: The reason for the long delays in completing the project was that the costs. … Although the objections described here are frequently raised, reason is because is still common in almost all levels of speech and occurs often in edited writing as well.
A similar charge of redundancy is made against the reason why, which is also a well-established idiom: The reason why the bill failed to pass was the defection of three key senators. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for reasoning

Contemporary Examples of reasoning

Historical Examples of reasoning

  • She was not a woman in the habit of reasoning, and had no conception of the difficulties in his way.

    Brave and Bold

    Horatio Alger

  • There was no reasoning which could help him in the midst of that puzzle.

  • Crane agreed with this reasoning, and it was decided to give the two horses a home trial.


    W. A. Fraser

  • The few moments' reasoning brought him to the point where he did not feel hurt.

    The Leopard Woman

    Stewart Edward White

  • This reasoning was of less avail than argument addressed to the general's fears.

British Dictionary definitions for reasoning



the act or process of drawing conclusions from facts, evidence, etc
the arguments, proofs, etc, so adduced



the faculty of rational argument, deduction, judgment, etc
sound mind; sanity
a cause or motive, as for a belief, action, etc
an argument in favour of or a justification for something
philosophy the intellect regarded as a source of knowledge, as contrasted with experience
logic grounds for a belief; a premise of an argument supporting that belief
by reason of because of
in reason or within reason within moderate or justifiable bounds
it stands to reason it is logical or obviousit stands to reason that he will lose
listen to reason to be persuaded peaceably
reasons of State political justifications for an immoral act


(when tr, takes a clause as object) to think logically or draw (logical conclusions) from facts or premises
(intr usually foll by with) to urge or seek to persuade by reasoning
(tr often foll by out) to work out or resolve (a problem) by reasoning
Derived Formsreasoner, noun

Word Origin for reason

C13: from Old French reisun, from Latin ratiō reckoning, from rērī to think


The expression the reason is because… should be avoided. Instead one should say either this is because… or the reason is that…
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for reasoning

late 14c., "exercise of the power of reason; act or process of thinking logically;" also "an instance of this;" verbal noun from reason (v.).



early 14c., resunmen, "to question (someone)," also "to challenge," from Old French raisoner "speak, discuss; argue; address; speak to," from Late Latin rationare "to discourse," from ratio (see reason (n.)). Intransitive sense of "to think in a logical manner" is from 1590s; transitive sense of "employ reasoning (with someone)" is from 1847. Related: Reasoned; reasoning.



c.1200, "intellectual faculty that adopts actions to ends," also "statement in an argument, statement of explanation or justification," from Anglo-French resoun, Old French raison "course; matter; subject; language, speech; thought, opinion," from Latin rationem (nominative ratio) "reckoning, understanding, motive, cause," from ratus, past participle of reri "to reckon, think," from PIE root *re(i)- "to reason, count" (cf. Old English rædan "to advise; see read (v.)).

Meaning "sanity; degree of intelligence that distinguishes men from brutes" is recorded from late 13c. Sense of "grounds for action, motive, cause of an event" is from c.1300. Middle English sense of "meaning, signification" (early 14c.) is in the phrase rhyme or reason. Phrase it stands to reason is from 1630s. Age of Reason "the Enlightenment" is first recorded 1794, as the title of Tom Paine's book.

Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with reasoning


see by reason of; in reason; it stands to reason; listen to reason; lose one's mind (reason); rhyme or reason; see reason; stand to reason; with reason.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.