the external world on the data of the senses; and nought remains for the immaterial soul but thinking, reflecting, and determining.

It must have been felt how obviously this position involves the whole subject in doubt. For if Matter is capable of the intuitive apprehension of the world in all its complexity, it is inconceivable that it should not also be capable of abstracting this intuition; wherefrom everything else would follow. Abstraction is of course nothing else than an elimination of the qualities attaching to things which are not necessary for general purposes, in other words, the individual and special differences. For instance, if I disregard, or abstract, that which is peculiar to the sheep, ox, stag, camel, etc., I reach the conception of ruminants. By this operation the ideas lose their intuitiveness, and