303. The whole world of reality, distinct from that of intellectual being, will forever remain unknown in Vico's system, which, for this reason, leads to the most rigid skepticism. What does he admit? The cognition by the mind of the mind's own work; and in this are comprised the acts of consciousness and all the purely ideal objects which we create in it. This, also, is admitted by the skeptics, no one of whom would deny that we have consciousness, and that there is an ideal world the work of this consciousness, or at least attested by it. If, then, we admit no criterion of truth but the made, we open the door to skepticism, and abandon the world of reality to fix ourselves in that of appearance. Nevertheless, so strange are human opinions, Vico thought directly the contrary; he believed that only with his system was it possible to refute skepticism. It is curious to hear him say with perfect seriousness: "The only means of destroying skepticism is to take this for the criterion of truth, that every one is certain of the truth which he makes." But what is the foundation of so odd an opinion? Let us listen to the philosopher himself, who says, indeed, many good things, but does not show how they may tend to the overthrow of skepticism: "Skeptics are always repeating that things _seem_ to them, but that they do not know what they really _are_. They confess effects, and consequently concede causes to them; but they assert that they do not know these causes, because they do not know the genus or form according to which things are made. Admit these propositions, and retort them thus: the comprehension of causes which contains all the genera and all the forms under which effects are produced, and the appearances of which the skeptic confessedly sees, although he denies that he knows their real essence, is found in the first truth which comprises all, and in which all, even to the last, are contained. And since this truth comprises all truths, it is infinite, it excludes none, and it has a superiority over every body, which is only an effect. This truth is consequently something spiritual; in other words, it is God, the God of the Christian. By this we must measure human truth; for human truth is that truth, the elements of which we have co-ordinated within us, and which, by means of certain postulates, we may extend and follow to infinity. By co-ordinating these truths we know and make them at one and the same time; and this is why, in this case, we have the genus and the form according to which we make."[32] [32] _Ibid._ 3.