rationality

rational +‎ -ity, from French rationalité, from Late Latin rationalitas (“rationality, reasonableness”), from Latin rationalis (“reasonable”)

rationality (usually uncountable, plural rationalities)

1. The quality or state of being rational; due exercise of reason; reasonableness.

   His sudden loss of rationality was brought on by excess drink.

2. Objective consideration.

   Such a discussion deserves rationality, not emotional gut reactions.

• rationalness

• “rationality”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• “rationality”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC.