In after life, when we ask _why_ we are sure of any kind of knowledge; the primary truths upon which _all_ our reasonings proceed, are always the presentations of our own mind. If we proceed to analyse accepted relativities, we soon perceive that Mind enters into our facts, and also into our sense-presentations. In particular, an examination of the noblest of all senses--the sense of sight--will convince any careful analyst that such is undeniably the case. The reader may recal Mr. Mill's words,[114]--"I do not believe that the real externality to us of anything, except other minds, is capable of proof." "For ourselves," says Professor Fraser, "we can conceive only--(1) An externality to our present and transient experience in _our own_ possible experience past and future, and (2) An externality to our own conscious experience, in the contemporaneous, as well as in the past or future experience of _other minds_"[115] In this view Mr. Mill (who quotes Fraser), entirely acquiesces, and in this same spirit he writes, "Matter may be defined, a Permanent Possibility of Sensation;"[116]--and adds that he can accept no other definition. Whether the reader can or cannot define Matter otherwise; he will, at all events, perceive that the Materialist assumes as _his_ primary postulate, that which is by no means _the_ primary fact accepted by Mankind. He starts with taking Matter for granted;--but, if he inquires, he will discover that Matter is known to him in the _second_ place only; he really _first_ knew Mind. When he questions sensation, or consciousness, he questions Mind; and, throughout his whole life, theoretical as well as practical, Mind is _nearer_ to him, and more _strongly_ evidenced, than any other "Possibility" whatsoever. Such, then, is the _first_ heavy burden of unauthorized postulation, which the Materialist's theory binds upon him. But, in the task of postulating without authority from Nature, it seems impossible to stop short. Mind, being an absolute necessity, must be got in some way--(from Matter of course)--evolved, correlated, secreted. No account is given _how_ Matter could have been thus transformed and glorified. Yet, in default of such account, it is impossible to divine _why_ that primary postulate ever existed at all.