I may be also blamed, when I am to touch upon many things which are mere matters of faculty, for having wrote in the Castilian Idiom: as an answer to this, it will be sufficient to reply, that no other reason is necessary to be given for so doing, than that I know of no reason against it. I do not deny, that there are truths, which should be hid from the vulgar, whose weakness exposes them to more danger by being informed, than they would be exposed to by remaining in ignorance; but this argument would militate with equal strength, against those truths going forth to the world in Latin, there being a great number of vulgar, among those who understand that language, and it passes easily from them, to those who understand no other than their mother tongue. I am so far from having the least intention to communicate pernicious matter to the public, that the principal design of this work, is to undeceive them in many points, which by being admitted as true, would be very prejudicial to them; nor is it reasonable, that a benefit which can be made universal, should not be enjoyed by every one. But do not from what I have advanced, conclude, that I have great confidence this work will be of eminent utility; for although my sole object is to propose the truth, it is possible, that in some instances I may want penetration to discern it, and in others, powers _to persuade it_; but I can with confidence assure you, that I write nothing, but what is conformable to my real sentiments. I look upon proposing, or attempting to prove singular opinions, only with a view of displaying a person’s ingenuity, as puerile and pedantic, and consider it as an employment, unworthy of every honest man. In conversation, these things may be tolerated by way of amusement, but the introducing them into writings, is an abuse, and a deceit upon the public. The noble use of reason, is to penetrate and enforce truths; the knack of puzzling others with sophistries, is the meanest faculty of the human understanding. Spiders, which in the brute creation are looked upon as vile, fabricate fine, but trifling threads; among mankind, none fabricate fine and firm ones, but excellent artists; the first, are emblems of subtle and sophistical works, the others of ingenious and solid ones. The common errors which I attack, do not always occupy the whole of the discourse in which I treat of them, and sometimes, many are comprehended in one and the same; either because they relate immediately to the matter of it, or because in pursuing the thread of the principal subject, they are found in the way, or fall in as it were by incidence. This method appeared to me the most convenient, as by writing a separate discourse upon every opinion I encounter, there being much to be said on some heads, and but little on others, there would result a compound or mass of parts extremely unequal.