If you tried to doubt everything you would not get as far as doubting anything. The game of doubting itself presupposes certainty.

At the core of all well-founded belief lies belief that is unfounded.

I act with complete certainty. But this certainty is my own.

To believe with certainty we must begin with doubting.

The human spirit glows from that small inner light of doubt whether we are right, while those who believe with certainty that they possess the right are dark inside and darken the world outside with cruelty, pain, and injustice.

Doubt cannot override a certainty