To discover all the sophistries and equivocations of captious reasonings, they have invented barbarous names that astonish those who hear them; and whilst we can only unravel all the tangles of this perplexing knot by drawing out one of the ends in the way proposed by geometricians, they have indicated a strange number of others in which the former are found included without knowing which is the best. And thus, in showing us a number of paths which they say conduct us whither we tend, although there are but two that lead to it, it is necessary to know how to mark them in particular. It will be pretended that geometry which indicates them with certainty gives only what had already been given by others, because they gave in fact the same thing and more, without heeding that this boon lost its value by abundance, and was diminished by adding to it. Nothing is more common than good things: the point in question is only to discriminate them; and it is certain that they are all natural and within our reach and even known to all mankind. But they know not how to distinguish them. This is universal. It is not among extraordinary and fantastic things that excellence is to be found, of whatever kind it may be. We rise to attain it and become removed from it: it is oftenest necessary to stoop for it. The best books are those, which those who read them believe they themselves could have written. Nature, which alone is good, is wholly familiar and common.