[Footnote 25: _Ibid._ vol. ii. p. 410.] Says Professor Tait, one of our most distinguished physicists: ‘There are ... things associated with living beings which, of course, no one in his senses can regard as physical. Even such things as consciousness and volition we have absolutely no reason, however vague, for classifying even in the smallest degree under the head of physics.’[26] [Footnote 26: _Recent Advances in Physical Science_, p. 70.] ‘I,’ writes Professor Huxley, ‘know nothing whatever, and never hope to know anything, of the steps by which the passage from molecular movement to states of consciousness is effected.’[27] And again, ‘All our knowledge is a knowledge of states of consciousness. “Matter” and “force” are, so far as we can know, mere names for certain forms of consciousness.‘[28] [Footnote 27: _Contemporary Review_, Nov. 1871: ‘Mr. Darwin and his Critics.’] [Footnote 28: _Lay Sermons_, p. 373.] Such disparity is there, then, between matter and mind, that it would be apparently as congruous to conceive of a thought as solidifying itself into a material object, as to conceive of any affection of material molecules as being the sole cause of thought. Hence, it follows that the Spencerian philosophy, which affirms the absolute distinctness of mind from matter, on the one hand; but, having no other structural elements _than_ matter in motion, on the other hand, seeks to educe mind from these, is surely incongruous, and fails. The demand is, that the primal atoms of the cosmic cloud, without a single logically added agent besides, have, by combining and recombining, by changing size and shape and intensifying the complexity of their motions, at last emerged into ‘I am,’ ‘I can,’ ‘I ought;’ that in effect they have written Faust and Hamlet, produced philosophies, discovered gravitation, calculated eclipses, realized the eternal nobility of right and the eternal baseness of wrong: in brief, have brought about the moral and intellectual manhood that is ours. What we _know_ by scientific evidence is this: that the persistence of force makes the relations of matter and force permanent. Says Faraday: ‘A particle of oxygen is ever a particle of oxygen, nothing can in the least wear it. If it enters into combination and reappears as oxygen—if it pass through a thousand combinations, animal, vegetable, mineral—if it lie hid for a thousand years and then be evolved—it is oxygen with its first qualities, neither more nor less. It has all its original force, and only that.’[29] [Footnote 29: _Philosophical Mag._, iv. 13, p. 235.]