The mind likes ideas. It asks for fresh ones, even half-baked ones. It busies itself cogitating. The mind is naturally curious, inventive, transgressive. Older persons are advised to keep mentally active so as to delay the decline of brain function. Research says mind work builds brain cells. Use it or lose it — and it doesn't matter what you think about, as long as your mind is exercised like a muscle. But ideas are not merely vitamins that serve to keep the mind alert; the mind also serves ideas. By turning them over and taking them apart the mind keeps ideas alive and prevents them from stultifying.
— James Hillman, The Force of Character