Andries van Dantzig, psychiater, emeritus hoogleraar psychotherapie aan de Universiteit van Amsterdam.

We may define 'faith' as a firm belief in something for which there is no evidence. When there is evidence, no one speaks of 'faith.' We do not speak of faith that two and two are four or that the earth is round. We only speak of faith when we wish to substitute emotion for evidence.

~ Bertrand Russell