The response leads us back to the origin of our notions of _Space_ and _Time_, on the the former of which mathematics is founded. The supposition that they are innate ideas is of course rejected by the materialist; for he looks upon innate ideas as fables; he considers them perceptions derived positively from the senses, but they do not belong to the senses alone, nor are they perceptions merely; “they are ideas, but ideas that without the sensuous perceptions of proximity and sequence could never have arisen. Nay, more—the perception of space must precede that of time,” for it is only through the former that we can reach the latter. The plainest laws of space, those which were the earliest impressions on the _tabula rasa_ of the infant mind, and which the hourly experience of life verifies, are called, by the mathematician, _axioms_, and on these simplest generalizations of our perceptions he bases the whole of his structure. Axioms, therefore, are the uniform results of experiments, the possible conditions of which are extremely limited, and the factors of which have been subjected to all these conditions. It follows from a denial of the absolute that all existence is concrete. Indeed, we may say that the corner stone of the edifice of materialism is embraced in the terse sentence of Moleschott—_all existence is existence through attributes_. Existence _per se_ (_Fürsichsein_) is a meaningless term, and substance apart from attribute, the _ens ineffabile_, is a pedantic figment and nothing more. Finally, there can be no attribute except through a relation.