The shrewd unlearned man of practice shall take that great book of nature, that illustrated digest of it, on his knees, to while away his idle hours with, in rich pastime, and smile to see there, all written out, that which he faintly knew, and never knew that he knew before; he will find there in sharp points, in accumulations, and percussions, that which his own experience has at length wearily, dimly, worked and worn into him. It is his own experience, exalted indeed, and glorified, but it is that which beckons him on to that which is yet beyond it; he shall read on, and smile, and laugh, and weep, and wonder at the power; but never dream that it is science, the new science--the science of nature--the product of the new organum of it applied to _human_ nature, and _human_ life. The abstract statement of that which the concrete exhibition veils, is indeed always there, though it lie never so close, in never so snug a corner; but it is there so artistically environed, that the reader who is not ready for it, who has not learned to disengage the principle from the instance, who has had no hint of an _illustrated tradition_ in it, will never see it; or if he sees it, he will think it is there by accident, or inspiration, and pass on. Here, in this open treatise upon the art of delivering and teaching of knowledge, the author lays down, in the most impressive terms, the necessity of a style which shall serve as a _veil_ of tradition, imperceptible or impenetrable to the uninitiated, and admitting 'only such as have by the help of a master, attained to the interpretation of dark sayings, or are able by their own genius to enter within the veil'; and after having distributed under many heads, the secret of this method of scientific communication, he asserts distinctly that there is no other mode of dealing with the popular belief and preconception, but the one just described--that same method which the teachers of the people have always instinctively adopted, whenever that which was new and contrary to the received doctrines, was to be communicated. 'For a man of judgment,' he says, 'must, of course, perceive, that there should be a difference in the teaching and delivery of knowledge, according to the _presuppositions, which he finds infused and impressed upon the mind of the learner_. For _that which is new and foreign from opinions received_, is to be delivered in ANOTHER FORM, from that which is _agreeable and familiar_. And, therefore, Aristotle, when he says to Democritus, "if we shall indeed _dispute_ and _not_ follow after _similitudes_," as if he would tax Democritus with being too full of _comparisons_, where he thought to reprove, really commended him.' There is no use in disputing in such a case, he thinks. 'For those whose doctrines are already _seated_ in popular opinion, have only to dispute or prove; but those whose doctrines are beyond the popular opinions, have a _double labour_; the