293. The x, therefore, of which Kant speaks, and the removal of which is one of the most important problems of philosophy, is nothing more than the faculty possessed by the soul to unite the conceptions of different things in one total conception, and to discover in it their mutual relations. This faculty is no new discovery, for the schools have all recognized it under one name or another. No one ever denied to the intellect the faculty of comparing; and comparison is the act whereby the intellect places two or more objects before its sight so as to perceive their mutual relations. In this act the intellect forms a total conception, of which the conceptions compared are a part. Thus we have seen that in geometry to verify the mutual relation of certain figures, we construct a new figure which includes them all, and is a sort of field whereon the comparison is made. This exposition of analytic and synthetic judgments will suffice for the present; as we proposed to treat of them here only in general, and as related to certainty; consequently we will not descend to their particular application to various ideas, the analysis of which belongs to other parts of this work. CHAPTER XXX. VICO'S CRITERION. 294. The doctrine of Vico on the criterion of truth is connected with the matter of the preceding chapters on immediate and mediate evidence. This philosopher thinks that the criterion consists in having made the truth which is known; that our cognitions then only are completely certain, and that they lose their certainty in proportion as the intellect loses its character of cause with respect to its objects. God, the cause of all, knows every thing perfectly: creatures, whose causality is very limited, are very limited in their cognitions; and if in any thing they may be likened to the infinite, it is in that ideal world which they construct for themselves, and extend at pleasure, stopped by no impassable limits.