Slender certainty is better than portentous falsehood..

Certitude is not the test of certainty..

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

For investor confidence, it is important that there is certainty about the future of Ireland in E.U..

The only certainty is death..

Certainty is the mark of the commonsense life-gracious uncertainty is the mark of the spiritual life..