Definition of "non-rational"
(often philosophy) Not within the domain of what can be understood or analyzed by reason; outside the competence of the rules of reason.
Quotations
Although some nonrational elements may be inconsistent with legal ideals, others—emotions and intuitions of certain types, imagination, judgment, rhetorical persuasiveness (considered below)—are fully consistent with those ideals.
1996, Paul Gewirtz, “On ‘I Know It When I See It’”, in The Yale Law Journal, volume 105, number 4, page 1036
(economics, social sciences, public policy) Not based on one's own interests; inconsistent with utility maximization.
Quotations
In the nature of things there must be causes that explain why an industrial enterprise—mill, factory, foundry, dairy, refinery—is located at just this or that place, and not somewhere else. Some of these causes are non-rational, such as accident and caprice. . The remaining causes are rational and economic; that is, the selected locality is deemed to offer certain advantages in production or marketing.
1896, Edward A. Ross, “The Location of Industries”, in The Quarterly Journal of Economics, volume 10, number 3, page 247