Reason

... Finally, what is Reason? You have often asked me; and this is my answer:
Whene'er the mist, that stands 'twixt God and thee,
[Sublimates] to a pure transparency,
That intercepts no light and adds no stain
There Reason is, and then begins her reign!
But alas!
------`tu stesso, ti fai grosso
Col falso immaginar, s' che non vedi
Ci' che vedresti, se l'avessi scosso.'
(Dante, Paradiso, Canto 1, lines 88-90)