The philosopher is in love with truth, that is, not with the changing world of sensation, which is the object of opinion, but with the unchanging reality which is the object of knowledge.
PlatoWhen the mind's eye rests on objects illuminated by truth and reality, it understands and comprehends them, and functions intelligently; but when it turns to the twilight world of change and decay, it can only form opinions, its vision is confused and its beliefs shifting, and it seems to lack intelligence.
Plato