Heinrich Heine said this quote

He always maintained that we fear something because we recognize it as fearsome through rational inferences, and that only the reason had any power; the heart had none. While I ate well and drank well, he kept demonstrating to me the advantages of reason... In striving after the positive, the poor man had argued away all life's splendour, all the sunbeams, all the faith and all the flowers, leaving nothing but the cold, positive grave.