And this is the system of reasoning now in vogue. This vicious system I adopted, and it hastened my fall into unbelief as a matter of course. Not one of all the most important things on earth admits of proof in this formal way. You cannot prove your own existence in this way. You cannot prove the existence of the universe. You cannot prove the existence of God. You cannot prove that there are such things as vice and virtue, good and evil. You cannot prove that men ought to marry, rear families, form governments, live in society, tell the truth, be honest, restrain their appetites and passions, or abstain from treachery and murder. All reasonings in favor of religion, virtue, society, philosophy, must rest on assumptions,--must take a number of things for granted,--must take for granted the truth and goodness of those instincts, sentiments, and natural affections which constrain us to be religious, social, and moral, independent of argument. All reasoning, to be of any use, must begin, not with doubt, but belief. The reasoning that begins with doubting every thing, and accepting nothing till it is proved by formal argument, will end in doubt of every thing that ought to be believed. It will end, not only in Atheism, but in boundless immorality, and in utter wretchedness and ruin. The man who would not be undone by his logic, must pity Descartes instead of admiring him, and instead of following him go just the contrary way. Descartes made a fool of himself, or his method of reasoning made a fool of him, the very first time he used it. His very first argument was a fallacy and a folly. He pretended, first, to doubt, and then to prove, his own existence. His argument was, 'I think; therefore I _exist_:' as if he could be more sure that he _thought_, than he was that he existed. He took his existence for granted when he said 'I think.' 20. Other things helped on the horrible change that was taking place in my soul. I got a taste for reading a different kind of works from those which I had been accustomed to read. I turned away from works on religion and duty, and began to read the works of the critical, destructive party. I turned away even from the best practical writers of the orthodox school, such as Baxter, Tillotson and Barrow, and read Theodore Parker, Martineau, W. F. Newman, W. J. Fox, and Froude. I also read Carlyle, Emerson, and W. Mackay, the metaphysical bore, and C. Mackay, the charming, fascinating, but not Christian poet. Theodore Parker became my favorite among the prose writers. His beautiful style and practical lessons had already reconciled me to his harsh expressions about the Bible, and to his contemptuous treatment of miracles; and now I had degenerated so far that I liked him for those very faults.