But let us suppose that Hume had lived to analyze Rousseau's Confessions. Would he not have urged with the force of truth, that to animalize a Man is to destroy his Manhood, to weaken his judgment and impair his Moral sense? Would he not have argued from Rousseau the depraved boy, to Rousseau the shopman and footman, and pointed out that in such cases Truth, Honesty, and Gratitude become mere names and shadows?--No one could have replied that Hume was wrong in fact and experience, but some might have said that _all_ which lowers the supremacy of the Moral sense lowers the Manhood of Man. As Hume admitted the fact of a Moral sense, he might possibly have felt the cogency of this argument. [75] No one who reads Hume's account of his own motives on various occasions will think it untrue to say that his judgment was largely influenced by his vanity. Compare for example his well-known letter to Dr. Blair of December 20th, 1765, with another to the same, dated 1st July, 1766;--the first a panegyric on the "celebrated Rousseau," the second a fierce invective against that "blackest and most atrocious villain." Who can help seeing that the motives of the eulogy are derived from a series of self-gratulations;--while the cause of the invective is a sharp wound given to the philosopher's self-love? [76] In the _Inquiry concerning Human Understanding_, Section XI., he puts this case: "As the universe shows wisdom and goodness, we infer wisdom and goodness. As it shows a particular degree of these perfections, we infer a particular degree of them, precisely adapted to the effect which we examine. But farther attributes or farther degrees of the same attributes, we can never be authorized to infer or suppose, by any rules of just reasoning." The argument of this section upon which Hume's limitations are based, is put into the mouth of a representative Epicurus; it is acute even to extreme subtlety, but it is also suicidal. The restraints applied to what he explains as the argument from effects to cause, and conversely down again from cause to other effects, cannot be maintained without dealing a death blow at the Inductive Philosophy. How little do we know of the material Universe, yet we apply the principle of gravitation to the Whole, seen and unseen. By its aid we find masses of radiant matter previously unknown, and predict events long before they are phenomenally apparent. The vast power of _extending_ knowledge which the Inductive principle asserts, will occur for our investigation in Chapter IV. Another Epicurean position contained in this same Section XI. has been quoted in a previous note, together with Hume's own reply to it; see pp. 101, 2 _ante_. A criticism of Hume's Tenth and Eleventh sections occupies a long note appended by Lord Brougham to his "Discourse on Natural Theology"--a volume I suppose accessible to almost all students of the science.