Ra`tion*al"i*ty (-ăl"ĭ*t?; 277), n.; pl. -ties (- tĭz). [F. rationalité, or L. rationalitas.] The quality or state of being rational; agreement with reason; possession of reason; due exercise of reason; reasonableness.

When God has made rationality the common portion of mankind, how came it to be thy inclosure?
Gov. of Tongue.

Well-directed intentions, whose rationalities will never bear a rigid examination.
Sir T. Browne.