Of his spiritual history down to the time of his marriage very little is known, for he made no earlier profession of faith. It is not to be supposed that he who was so scrupulous of truth, so single-minded in every relation of life, would accept the religious belief of his fathers without satisfying his conscience as to the rightness of its claims. Yet none of his letters or writings of that period show any trace[60] of that stress of soul through which at one time or another every sincere and earnest seeker after truth must pass before he finds anchorage. Certain it is that he clung with warm attachment to the little self-contained sect amongst whom he had been brought up. Its influence, though contracting his activities by precluding all Christian communion or effort outside their circle, and cutting him off from so much that other Christian bodies hold good, fenced him effectually from dreams of worldliness, and furnished him with that very detachment which was most essential to his scientific pursuits. One month after his marriage he made his confession of sin and profession of faith before the Sandemanian Church. It was an act of humility the more striking in that it was done without any consultation with his wife, to whom he was so closely attached, and who was already a member of the congregation. When she asked him why he had not told her what he was about to do, he replied: “That is between me and my God.” In 1844 he wrote to Lady Lovelace as follows:-- “You speak of religion, and here you will be sadly disappointed in me. You will perhaps remember that I guessed, and not very far aside, your tendency in this respect. Your confidence in me claims in return mine to you, which indeed I have no hesitation in giving on fitting occasions, but these I think are very few, for in my mind religious conversation is generally in vain. _There is no philosophy in my religion._ I am of a very small and despised sect of Christians, known, if known at all, as Sandemanians, and our hope is founded on the faith that is in Christ. But though the natural works of God can never by any possibility come in contradiction with the higher things that belong to our future existence, and must with everything concerning Him ever glorify Him, still I do not think it at all necessary to tie the study of the natural sciences and religion together, and, in my intercourse with my fellow creatures, that which is religious and that which is philosophical have ever been two distinct things.” His own views were stated by himself at the commencement of a lecture on _Mental Education_ in 1854:--