“The use of the intellect ... is twofold. By the one use concepts, both of things and of relations, are themselves _given_. This is the _real use_. By the other use concepts, whencesoever given, are merely _subordinated_ to each other, the lower to the higher (the common attributes), and compared with one another according to the principle of contradiction. This is called the _logical use_.... Empirical concepts, therefore, do not become intellectual in the _real sense_ by reduction to greater universality, and do not pass beyond the type of sensuous cognition. However high the abstraction be carried, they must always remain sensuous. But in dealing with things _strictly intellectual_, in regard to which the _use of the intellect_ is _real_, intellectual concepts (of objects as well as of relations), are given by the very nature of the intellect. They are not abstracted from any use of the senses, and do not contain any form of sensuous knowledge as such. We must here note the extreme ambiguity of the word _abstract_.... An intellectual concept _abstracts_ from everything sensuous; it is not _abstracted_ from things sensuous. It would perhaps be more correctly named _abstracting_ than _abstract_. It is therefore preferable to call the intellectual concepts _pure ideas_, and those which are given only empirically _abstract ideas_.”[690] “I fear, however, that Wolff, by this distinction between the sensuous and the intellectual, which for him is merely logical, has checked, perhaps wholly (to the great detriment of philosophy), that noblest enterprise of antiquity, the investigation of _the nature of phenomena and noumena_, turning men’s minds from such enquiries to what are very frequently only logical subtleties. Philosophy, in so far as it contains the _first principles_ of the use of the _pure intellect_, is _metaphysics_.... As empirical principles are not to be found in metaphysics, the concepts to be met with in it are not to be sought in the senses but in the very nature of the pure intellect. They are not _connate_ concepts, but are _abstracted_ from laws inherent in the mind (_legibus menti insitis_), and are therefore _acquired_. Such are the concepts of possibility, existence, necessity, substance, cause, etc. with their opposites or correlates. They never enter as parts into any sensuous representation, and therefore cannot in any fashion be abstracted from such representations.”[691]