rationality (n.)

1620s, "quality of having reason;" 1650s, "fact of being agreeable to reason," from French rationalité and directly from Late Latin rationalitas "reasonableness, rationality" (also source of Spanish racionalidad, Italian razionalita), from Latin rationalis "of or belonging to reason, reasonable" (see rational). Middle English had racionabilite "the faculty of reason" (early 15c.), from Latin rationabilitas.