“Doubt is nothing but a trivial agitation on the surface of the soul, while deep down there is a calm certainty.”

“What is truly profound is thought to be stupid and trivial, or worse, boring, while what is actually stupid and trivial is thought to be profound. That is what it means to fly upside down.”

“We must doubt the certainty of everything which passes through the senses, but how much more ought we to doubt things contrary to the senses, such as the existence of God and the soul.”

“If a man will begin with certainties, he shall end in doubts; but if he will be content to begin with doubts he shall end in certainties.”

“So my great love for thee lies tranquil, deep,
Forever; though above it passions fierce,
Ambition, hatred, jealousy; like waves
That seem from earth’s core to the sky to leap,
But ocean’s depths can never really pierce;
Hide its great calm, while all the surface raves.”

“Is it possible this triviality is a code of some sort? the Brain wondered. But how could it be … unless there's more to these emotional inconsequentials and this talk of a God than appears on the surface?
The Brain had begun its career in logics as a pragmatic atheist. Now doubts began to creep into its computations, and it classified doubt as an emotion.”

“The opposite of faith is not doubt, it’s certainty.”

“The Buddhists say if you meet somebody and your heart pounds, your hands shake, your knees go weak, that’s not the one. When you meet your ‘soul mate’ you’ll feel calm. No anxiety, no agitation.”

“Surely there is something in the unruffled calm of nature that overawes our little anxieties and doubts; the sight of the deep-blue sky and the clustering stars above seems to impart a quiet to the mind.”

“It is useless to seek the soul of things beneath their surface, for their surface is their soul.”