2. _As to Qualities and Substance, or Phenomena and Reality_.--As phenomena appear only in conjunction, we are compelled, by the constitution of our nature, to think them conjoined in and by something; and as they are phenomena, we can not think them phenomena of nothing, but must regard them as properties or qualities of something.[283] Now that which manifests its qualities--in other words, that in which the appearing causes inhere, that to which they belong--is called their _subject_, or _substance_, or _substratum_.[284] The subject of one grand series of phenomena (as, _e.g._, extension, solidity, figure, etc.) is called _matter_, or _material substance_. The subject of the other grand series of phenomena (as, _e.g._, thought, feeling, volition, etc.) is termed _mind_, or _mental substance_. We may, therefore, lay it down as an undisputed truth that consciousness gives, as an ultimate fact, a primitive duality--a knowledge of the _ego_ in relation and contrast to the _non-ego_, and a knowledge of the _non-ego_ in relation and contrast to the _ego_[285] Natural Dualism thus establishes the existence of two worlds of _mind_ and _matter_ on the immediate knowledge we possess of both series of phenomena; whilst the Cosmothetic Idealists discredit the veracity of consciousness as to our immediate knowledge of material phenomena, and, consequently, our _immediate knowledge of the existence of matter_.[286] [Footnote 283: Ibid., vol. i. p. 137.] [Footnote 284: Ibid., vol. i. p. 137.] [Footnote 285: Ibid., vol. i. p. 292.] [Footnote 286: Ibid., vol. i. pp. 292, 295.]