Doubt is the first ray of illumination

Play with reason and doubt will close all the gates

Knock on the heart’s emotions and its gates will be widely opened, but nock on reason and doubt will come charging at you

It's true not because it's beyond doubt, but because we believe it to be true. We make it true. We are safe as long as no one can disprove us

I believe despite my doubts, belief gives me power reason takes away

Doubt increases emptiness; full faith keeps the body heavy and full of courage!