The obvious doctrine of the above quotations is, that we have an immediate knowledge of the "_existence_ of matter" as well as of "the _phenomena_ of matter;" that is, we know "_substance_" as immediately and directly as we know "_qualities_." Phenomena are known only as inherent in substance; substance is known only as manifesting its qualities. We never know qualities without knowing substance, and we can never know substance without knowing qualities. Both are known in one concrete act; substance is known quite as much as quality; quality is known no more than substance. That we have a direct, immediate, presentative "face to face" knowledge of matter and mind in every act of consciousness is asserted again and again by Hamilton, in his "Philosophy of Perception."[287] In the course of the discussion he starts the question, "_Is the knowledge of mind and matter equally immediate?_" His answer to this question may be condensed in the following sentences. In regard to the immediate knowledge of _mind_ there is no difficulty; it is admitted to be direct and immediate. The problem, therefore, exclusively regards the intuitive perception of the qualities of _matter_. Now, says Hamilton, "if we interrogate consciousness concerning the point in question, the response is categorical and clear. In the simplest act of perception I am conscious of _myself_ as a perceiving _subject_, and of an external _reality_ as the object perceived; and I am conscious of both existences in the same indivisible amount of intuition."[288] Again he says, "I have frequently asserted that in perception we are conscious of the external object, immediately and _in itself_." "If, then, the veracity of consciousness be unconditionally admitted--_if the intuitive knowledge of matter and mind_, and the consequent reality of their antithesis, be taken as truths," the doctrine of Natural Realism is established, and, "without any hypothesis or demonstration, the _reality of mind_ and the _reality of matter_."[289] [Footnote 287: Philosophy of Sir William Hamilton, part ii.] [Footnote 288: Ibid., p. 181.] [Footnote 289: Ibid., pp. 34, 182.]