But let us understand that the intellectual life and the religious life are as distinct as the scientific and the artistic lives. They may be led by the same person, but by the same person in different moods. They coincide on some points, accidentally. Certainly, the basis of high thinking is perfect honesty, and honesty is a recognized religious virtue. Where the two minds differ is on the importance of authority. The religious life is based upon authority, the intellectual life is based upon personal investigation. From the intellectual point of view I cannot advise you to restrain the spirit of investigation, which is the scientific spirit. It may lead you very far, yet always to truth, ultimately,--you, or those after you, whose path you may be destined to prepare. Science requires a certain inward heat and heroism in her votaries, notwithstanding the apparent coldness of her statements. Especially does she require that intellectual fearlessness which accepts a proved fact without reference to its personal or its social consequences. LETTER V. TO A FRIEND WHO SEEMED TO TAKE CREDIT TO HIMSELF, INTELLECTUALLY, FROM THE NATURE OF HIS RELIGIOUS BELIEF. Anecdote of a Swiss gentleman--Religious belief protects traditions, but does not weaken the critical faculty itself--Illustration from the art of etching--Sydney Smith--Dr. Arnold--Earnest religious belief of Ampère--Comte and Sainte-Beuve--Faraday--Belief or unbelief proves nothing for or against intellectual capacity. I happened once to be travelling in Switzerland with an eminent citizen of that country, and I remember how in speaking of some place we passed through he associated together the ideas of Protestantism and intellectual superiority in some such phrase as this: "The people here are very superior; they are Protestants." There seemed to exist, in my companion's mind, an assumption that Protestants would be superior people intellectually, or that superior people would be Protestants; and this set me thinking whether, in the course of such experience as had fallen in my way, I had found that religious creed had made much difference in the matter of intellectual acumen or culture.