the mind > mental capacity > understanding > intelligence, cleverness > [adjective] > appealing to intelligence (3)
That appeals to or engages the intellect; requiring the exercise of understanding.
figurative. Rich in wealth, fit to be ‘sucked’ (quot. 1627); of rich intellectual quality, full of interest (the opposite of ‘dry’). colloquial.
Intellectual; appealing to the intellect (rather than to the emotions); clever.