rationality

American  

[rash-uh-nal-i-tee] / ˌræʃ əˈnæl ɪ ti /

noun

rationalities plural

1. the state or quality of being rational.

2. the possession of reason.

3. agreeableness to reason; reasonableness.

4. the exercise of reason.

5. a reasonable view, practice, etc.

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rationality British  

/ ˌræʃəˈnælɪtɪ /

noun

1. the state or quality of being rational or logical

2. the possession or utilization of reason or logic

3. a reasonable or logical opinion

4. economics the assumption that an individual will compare all possible combinations of goods and their prices when making purchases

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Other Word Forms

Derived Forms

• antirationality
  noun
• nonrationality
  noun

Inflected Forms

Nouns

• rationalities
  plural

Etymology

Origin of rationality

First recorded in 1560–70, rationality is from the Late Latin word ratiōnālitās reasonableness. See rational, -ity

Explanation

Use the noun rationality to refer to the state of being sensible or having good judgment. People may question your rationality if you insist on jumping into freezing water in January and skydiving for the rest of the year. The noun rationality also means the state of being agreeable to reason or being based on logic. If you have to pick a pre-school for your child, you should base your decision on rationality and not an illogical reaction, such as how many of the kids eventually go to Ivy League universities. The newer school may look better on the surface, but the older building may have better teachers, a more interesting curriculum, and be closer to your home.

Example Sentences

See Examples For:

rationality rationalities

Only the practical rationality and moral rootedness of the New World can redeem the old.

From The Wall Street Journal ● Feb. 27, 2026

"These rules lack humanity and rationality, and they oppress us every day."

From Barron's ● Jan. 9, 2026

We comfort the comfortable, and we look for hope in norms and in institutions and in rationality.

From Slate ● Dec. 17, 2025

It’s the second factor that often keeps takeover bids alive long after the proposed deals lose their economic rationality.

From Los Angeles Times ● Dec. 11, 2025

Yet habit had overcome her rationality and had made her ask me: “Boy, do you steal?”

From "Black Boy" by Richard Wright

She was as mired in the notions of the Old World, in its rationalities, its explanations, its conventions, and its Protestantism, as my father was a product of his Catholicism and his own colonial past.

From New York Times ● Aug. 17, 2022

They have to be continually reproduced, against the everyday resistances and rationalities that throw inequality into question.

From Slate ● Nov. 22, 2019

As an economist, I eschew the soft-headed convenience of ready-made ideologies, together with their carrying rationalities, turning upon intellectual vulgarities I haven’t the stomach to bear.

From Economist ● Nov. 26, 2013

Underlying all this confusion is the problem that we don't have a way of ranking rationalities, so that the word means something more to a moral agent than it does to an economist.

From The Guardian ● Aug. 21, 2012

They seem like stray vestiges of that primordial irrationality, from which all our rationalities have been evolved.

From Memories and Studies by James, Henry

Related Words

• coherence
• good sense
• sanity