You may say that the individual in question is a moral man, and you think not unwilling to be convinced of his errors; that is, he sees the moral truth of Christianity, but cannot be persuaded of it intellectually. I should say that such a state of mind is one of very painful trial, and should be treated as such; that it is a state of mental disease, which like many others is aggravated by talking about it, and that he is in great danger of losing his perception of moral truth as well as of intellectual, of wishing Christianity to be false as well as of being unable to be convinced that it is true. There are thousands of Christians who see the difficulties which he sees quite as clearly as he does, and who long as eagerly as he can do for that time when they shall know, even as they are known. But then they see clearly the difficulties of unbelief, and know that even intellectually they are far greater. And in the mean while they are contented to live by faith, and find that in so doing, their course is practically one of perfect light; the moral result of the experiment is so abundantly satisfactory, that they are sure that they have truth on their side.
Thomas Arnold, letter to the Lady Francis Egerton, February 15, 1832, in Arthur Penrhyn Stanley, ed., The Life and Correspondence of Thomas Arnold, D.D., vol. 1 (London: B. Fellowes, 1844), pp. 281-82.