1. Relating to cause; not physical; mental. "Moral
philosophy was
his chiefest end; for the rational, the natural, and
mathematics . . . Were
but simple pastimes in collation of the other." (Sir T. North)
2. Having cause, or the
faculty of reasoning; endowed with
cause or understanding; reasoning. "It is our
glory and
happiness to have a
rational nature." (Law)
3. Agreeable to cause; not absurd, preposterous, extravagant, foolish, fanciful, or the like; clever; judicious; as,
rational conduct; a
rational man.
4.
Expressing the type, structure, relations, and reactions of a compound; graphic; said of formulae. See Formula. Rational horizon.
See Horizon, 2 .
Rational quantity, one elicited by the statements of the patient himself and not as the result of a physical examination.
Synonym: Sane, sound, intelligent, reasonable, sensible, clever, discreet, judicious.
Rational, reasonable. Rational has reference to cause as a faculty of the mind, and is opposed to traditional; as, a rational being, a rational state of mind, rational views, etc. In these cases the speculative cause is more particularly, referred to. Reasonable has reference to the exercice of this faculty for practical purposes, and means, governed or directed by cause; as, reasonable prospect of success. "What higher in her society thou find'st Likable, human, rational, love still." (Milton) "A law may be reasonable in itself, although a man does not let it, or does not know the cause of the lawgivers." (Swift)
Origin: L. Rationalis: cf. F. Rationnel. See Ratio, Cause, and cf. Rationale.
Source: Websters Vocabulary