Definify.com
Webster 1913 Edition
Rational
Ra′tion-al
(răsh′ŭn-al)
, Adj.
1.
Relating to the reason; not physical; mental.
Moral philosophy was his chiefest end; for the
rational
, the natural, and mathematics . . . were but simple pastimes in comparison of the other. Sir T. North.
2.
Having reason, or the faculty of reasoning; endowed with reason or understanding; reasoning.
It is our glory and happiness to have a
rational
nature. Law.
3.
Agreeable to reason; not absurd, preposterous, extravagant, foolish, fanciful, or the like; wise; judicious;
as,
rational
conduct; a rational
man.4.
(Chem.)
Expressing the type, structure, relations, and reactions of a compound; graphic; – said of formulae. See under
Formula
. Rational horizon
. (Astron.)
See
– Horizon
, 2 (b)
. Rational quantity
(Alg.)
, one that can be expressed without the use of a radical sign, or in exact parts of unity; – opposed to
– irrational
or radical quantity
. Rational symptom
(Med.)
, one elicited by the statements of the patient himself and not as the result of a physical examination.
Syn. – Sane; sound; intelligent; reasonable; sensible; wise; discreet; judicious.
– Rational
, reasonable
. Rational has reference to reason as a faculty of the mind, and is opposed to irrational; as, a
In these cases the speculative reason is more particularly, referred to. Reasonable has reference to the exercise of this faculty for practical purposes, and means, governed or directed by reason; rational
being, a rational
state of mind, rational
views, etc. as,
. reasonable
desires or plans; a reasonable
charge; a reasonable
prospect of successWhat higher in her society thou find’st
Attractive, human,
Attractive, human,
rational
, love still. Milton.
A law may be
reasonable
in itself, although a man does not allow it, or does not know the reason of the lawgivers. Swift.
Ra′tion-al
,Noun.
A rational being.
Young.
Webster 1828 Edition
Rational
RA'TIONAL
,Adj.
1.
Having reason or the faculty of reasoning; endowed with reason; opposed to irrational; as, man is a rational being; brutes are not rational animals.It is our glory and happiness to have a rational nature.
2.
Agreeable to reason; opposed to absurd; as a rational conclusion or inference; rational conduct.3.
Agreeable to reason; not extravagant.4.
Acting in conformity to reason; wise; judicious; as a rational man.RA'TIONAL
,Noun.
Definition 2024
rational
rational
See also: rațional
English
Alternative forms
- rationall (obsolete)
Adjective
rational (comparative more rational, superlative most rational)
- Capable of reasoning.
- Man is a rational creature.
- 2001, Mark Sainsbury, chapter 1, in Logical Forms — An Introduction to Philosophical Logic, 2nd edition, Blackwell Publishing, ISBN 978-0-63121-679-7, §7, page 32:
- The utility of valid arguments is a monument to our frailty: to the fact that we are not completely rational beings.
- Logically sound; not contradictory or otherwise absurd.
- His statements were quite rational.
- (of a person or personal characteristics) Healthy or balanced intellectually; exhibiting reasonableness.
- rational conduct
- 2014 June 21, “Magician’s brain”, in The Economist, volume 411, number 8892:
- The [Isaac] Newton that emerges from the [unpublished] manuscripts is far from the popular image of a rational practitioner of cold and pure reason. The architect of modern science was himself not very modern. He was obsessed with alchemy.
- (mathematics, arithmetic, number theory, not comparable) Of a number, capable of being expressed as the ratio of two integers.
- ¾ is a rational number, but √2 is an irrational number.
- (mathematics, arithmetic, not comparable) Of an algebraic expression, capable of being expressed as the ratio of two polynomials.
- (chemistry) Expressing the type, structure, relations, and reactions of a compound; graphic; said of formulae.
Antonyms
- (reasonable): absurd, irrational, nonsensical
- (capable of reasoning): arational, irrational, non-rational
- (number theory): irrational
Related terms
Terms etymologically related to rational
Translations
capable of reasoning
|
reasonable; not absurd
|
|
arithmetic: of a number
|
arithmetic: of an algebraic expression
|
Noun
rational (plural rationals)
- (mathematics) A rational number: a number that can be expressed as the quotient of two integers.
- The quotient of two rationals is again a rational.
Translations
rational number — see rational number
Etymology 2
From Old French rational, from Medieval Latin rationale (“a pontifical stole, a pallium, an ornament worn over the chasuble”), neuter of Latin rationalis (“rational”), for which see the first etymology. Translation of λογεῖον (logeîon) or perhaps λόγιον (lógion, “oracle”) in the Septuagint version of Exodus 28.
Noun
rational (plural rationals)
- the breastplate worn by Israelite high priests
- 1609, Douay-Rheims Bible, Exodus 28:15
- And thou shalt make the rational of judgment with embroidered work of divers colours, according to the workmanship of the ephod, of gold, violet, and purple, and scarlet twice dyed, and fine twisted linen.
Translations
Translations
References
- rational in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913
- rational in The Century Dictionary, The Century Co., New York, 1911