rational

Use the adjective rational to describe people or ideas that operate according to logic or reason. While your brother has an artistic temperament, you have a rational one.

Rational comes from the Latin word rationalis, meaning reasonable or logical. If you're rational, you do things based on logic, as opposed to impulse or whimsy. The original meaning in English was of something endowed with the ability to reason. Before we knew how smart some animals like dolphins are, writers liked to distinguish rational human minds from the supposedly irrational, instinctual minds of animals.

Definitions of rational
  1. adjective
    consistent with or based on or using reason
    rational behavior”
    “a process of rational inference”
    rational thought”
    Synonyms:
    logical
    capable of or reflecting the capability for correct and valid reasoning
    coherent, logical, lucid
    capable of thinking and expressing yourself in a clear and consistent manner
    demythologised, demythologized
    having mythical elements removed
    intelligent, reasoning, thinking
    endowed with the capacity to reason
    reasonable, sane
    marked by sound judgment
    reasonable, sensible
    showing reason or sound judgment
    sane
    mentally healthy; free from mental disorder
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    Antonyms:
    irrational
    not consistent with or using reason
    incoherent
    without logical or meaningful connection
    illogical, unlogical
    lacking in correct logical relation
    blind, unreasoning
    not based on reason or evidence
    reasonless
    not endowed with the capacity to reason
    nonrational
    not based on reason
    superstitious
    showing ignorance of the laws of nature and faith in magic or chance
    unreasonable
    not reasonable; not showing good judgment
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  2. adjective
    of or associated with or requiring the use of the mind
    “the triumph of the rational over the animal side of man”
    synonyms: intellectual, noetic
    mental
    involving the mind or an intellectual process
  3. adjective
    having its source in or being guided by the intellect (as distinguished from experience or emotion)
    “a rational analysis”
    Synonyms:
    intellectual
    appealing to or using the intellect
  4. adjective
    capable of being expressed as a quotient of integers
    rational numbers”
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    Antonyms:
    irrational
    real but not expressible as the quotient of two integers
  5. noun
    an integer or a fraction
    synonyms: rational number
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    types:
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    fraction
    the quotient of two rational numbers
    fixed-point part, mantissa
    the positive fractional part of the representation of a logarithm; in the expression log 643 = 2.808 the mantissa is .808
    common fraction, simple fraction
    the quotient of two integers
    improper fraction
    a fraction whose numerator is larger than the denominator
    proper fraction
    a fraction with a numerator smaller than the denominator
    complex fraction, compound fraction
    a fraction with fractions in the numerator or denominator
    continued fraction
    a fraction whose numerator is an integer and whose denominator is an integer plus a fraction whose numerator is an integer and whose denominator is an integer plus a fraction and so on
    type of:
    real, real number
    any rational or irrational number
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