September 21, 1830

......He told me that facts gave birth to, and were the absolute ground of principles; to which I said, that unless he had a principle of selection, he would not have taken notice of those facts upon which he had grounded his principle. You must have a lantern in your hand to give light, otherwise all the materials in the world are useless, for you could not arrange them. "But then," said Mr.--, "that principle of selection came from facts!" - "To be sure!" I replied; "but there must have been an antecedent light to see those antecedent facts. The relapse may be carried in imagination backwards for ever, - but go back as you may, you cannot come to a man without a previous aim or principle. He then asked me what I had to say to Bacon's induction: I told him I had a good deal to say, if need were; but that it was perhaps enough for the occasion to remark, that what he was evidently taking for the Baconian induction was mere deduction - a very different thing.