If, on the other hand, the idea of poetry as pure imagination had not remained firmly at the foundation of Vico's thought, in spite of all the confusions and inconsistencies in which it became involved, and had not been at work underground, so to speak, in the New Science, it would have been difficult or perhaps impossible to understand the leading conception which dominates his philosophy of mind, closely connected as it is with that idea. This is the conception of the mind as a development, or, to use Vico's own words, a progress or unfolding (_corso, spiegamento_); a conception which improved upon, though it did not explicitly contradict, the ordinary view which was almost exclusively confined to the enumeration and classification of the mind's faculties. The doctrine of imaginative universals as spontaneous mental products, rudimentary universals but not without an element of truth in them, was at least an adequate weapon against the empirical theory which made civilisation the outcome of a highly developed and rational practical wisdom and the personal labour of God or of wise men who must have sprung from the earth or fallen from heaven in some unaccountable manner. Vico clearly stated the dilemma between the two, and only two, possible explanations of the origin of society. Either it came from the reflection of wise men, or from a certain human feeling and instinct among brutish men. He accepted the latter solution, that of "brutes" which gradually became human: the theory, that is, of the evolution of thought from the imaginative to the rational universal, and the progress of social relations from force to equity. But was this an adequate foundation for "ideal history" or the philosophy of mind? In the philosophy of mind, it could be translated into a similar if not identical view--the doctrine which, owing to Cartesianism and a certain recrudescence of the Scholasticism of Duns Scotus, lasted down to Vico's own times and expressed the life of the mind by the successive stages of the concept, obscurity, confusion, clarity and distinctness. Leibniz, as is well known, made a special study of obscure and confused perceptions, the _"petites perceptions."_ The doctrine was essentially intellectualistic, since the concepts, however confused or obscure, were never anything else than concepts: and hence it was unable to account either for poetry or even for mental development, the dialectic of which cannot be understood if it is regarded as consisting of merely quantitative differences. Such differences are in reality not differences at all, but identities and therefore the negation of change: and in fact the whole of this school of thought was anti-aesthetic and static, devoid both of a true theory of imagination and a true theory of development. Vico's thought, on the other hand, was averse to intellectualism and in sympathy with imagination: it was entirely dynamic and evolutionary. For Vico, mind is an eternal drama: