the mind > mental capacity > understanding > reason, faculty of reasoning > [noun] > basis in reason (11)
The fact or quality, in an abstract thing, of being based on, or in accordance with, reason.
figurative. Scope, opportunity; reasonable occasion or ground. Usually in negative contexts with for, †of.
The fact or condition of being based on, or in accordance with, reason or rationalism.
The quality or state of being rational. Cf. rationality, n.