Leibnitz, Descartes.[95] He found these authors in a condition of such perpetual contradiction among themselves, that he formed the chimerical design of reconciling them with one another.  This was tedious, so he took up another method, on which he congratulated himself to the end of his life.  It consisted in simply adopting and following the ideas of each author, without comparing them either with one another or with those of other writers, and above all without any criticism of his own.  Let me begin, he said, by collecting a store of ideas, true or false, but at any rate clear, until my head is well enough stocked to enable me to compare and choose.  At the end of some years passed “in never thinking exactly, except after other people, without reflecting so to speak, and almost without reasoning,” he found himself in a state to think for himself.  “In spite of beginning late to exercise my judicial faculty, I never found that it had lost its vigour, and when I came to publish my own ideas, I was hardly accused of being a servile disciple."[96]

To that fairly credible account of the matter, one can only say that this mutually exclusive way of learning the thoughts of others, and developing thoughts of your own, is for an adult probably the most mischievous, where it is not the most impotent, fashion in which intellectual exercise can well be taken.  It is exactly the use of the judicial faculty, criticising, comparing, and defining, which is indispensable in order that a student should not only effectually assimilate the ideas of a writer, but even know what those ideas come to and how much they are worth.  And so when he works at ideas of his own, a judicial faculty which has been kept studiously slumbering for some years, is not likely to revive in full strength without any preliminary training.  Rousseau was a man of singular genius, and he set an extraordinary mark on Europe, but this mark would have been very different if he had ever mastered any one system of thought, or if he had ever fully grasped what systematic thinking means.  Instead of this, his debt to the men whom he read was a debt of piecemeal, and his obligation an obligation for fragments; and this is perhaps the worst way of acquiring an intellectual lineage, for it leaves out the vital continuity of temper and method.  It is a small thing to accept this or that of Locke’s notions upon education or the origin of ideas, if you do not see the merit of his way of coming by his notions.  In short, Rousseau has distinctions in abundance, but the distinction of knowing how to think, in the exact sense of that term, was hardly among them, and neither now nor at any other time did he go through any of that toilsome and vigorous intellectual preparation to which the ablest of his contemporaries, Diderot, Voltaire, D’Alembert, Turgot, Condorcet, Hume, all submitted themselves.  His comfortable view was that “the sensible and interesting conversations of a woman of merit are more proper to form a young man than all the pedantical philosophy of books."[97]