That Vico's obscurity, his mistake or mistakes, is due to the confusion or lack of distinction in his theory of knowledge mentioned above, on the question of the relations between philosophy, history and empirical science--a confusion which exists no less in his actual thought on the problems of the mind and history of man--that this is so can be seen by observing how philosophy, history and empirical science pass into each other by turns in Vico's mind, and vitiating each other in turn produce the perplexities, ambiguities, exaggerations and hasty statements which perturb the reader of the New Science. The philosophy of mind masquerades now as empirical science, now as history: empirical science now as philosophy, now as history: and historical propositions assume the universality of philosophical principles or the generality of empirical schemata. For example, the philosophy of man undertakes to determine the forms, categories or ideal moments of mind in their necessary succession, and in this aspect it well deserves the title or definition of "eternal ideal history" according to which particular histories proceed in time; while no fragment however small of actual history can be conceived in which this ideal history is not present. But, since ideal history is also for Vico the empirical determination of the order in which the forms of civilisations, states, languages, styles, and kinds of poetry succeed one another, it comes about that he conceives the empirical series as identical with the ideal series, and as deriving validity from it. Hence he asserts that this series must always be exactly reproduced in the facts, "even if infinite worlds were produced from time to time through eternity": an assertion which is plainly false, since there is no reason why the empirical fact of Greek or Roman aristocracy should be repeated for ever, with a "must have been, must be now, must be hereafter"; or why civilisations should rise and fall precisely as did those of antiquity. And this very treatment of the empirical course of events as absolute threw a shadow of empiricism over their ideal course; since the latter once identified with the former took over its empirical and temporal character instead of the eternal and extra--temporal character which it had as originally conceived. The same must be said of the various forms of mind which, as ideal and extra--temporal, are always all present in every fact; but Vico, by confusing them with the real and concrete facts which empirical science splits up into its schemata, destroyed them in their ideal form and distinction as soon as he had stated them. It is true that the moment of force is not that of justice; but the empirical type of barbaric society founded upon force, precisely because it is a representative and approximative determination, and is referred to a concrete and total state of things, contains not only force but justice as well; and when this ideal moment and this type of society are interchanged and treated as identical, on the one hand the philosophical concept of force is confused with that of justice and becomes impure, contradictory and incoherent, and finally annuls itself: on the other, the empirical type of barbaric society becomes exaggerated and unduly rigid. The confusion between the philosophic and the empirical is clearly expressed in Vico's aphorism defining the nature of things. "Nature of things is nothing else than their production at certain times and in certain manners: and whenever these latter are of such a kind, then the things produced are of such a kind and no other." Here we see the confusion between time and manner, between ideal and empirical genesis. Similarly, it is perfectly true that history ought to proceed in harmony with philosophy, and that a philosophical absurdity can never be a historical event: but, since the distinction between philosophy and empirical science was not drawn by Vico, when evidence was lacking and philosophy therefore inapplicable he felt no less sure of attaining truth. He merely filled the gap with a conjecture supplied by the schema of empirical science, and persuaded himself that he had fallen back on a "metaphysical proof." Or again, if he found himself faced by uncertain facts, instead of patiently waiting till the discovery of further evidence should dispel the doubt, he cut the knot by accepting the facts, as he put it, in conformity with laws: which always means the empirical schema. A legitimate method, doubtless, when treated as hypothetical.