as a propagandist.  Like pictures, they impress the mind of the hearer with a vivid sense of reality.  “Every one knows the exquisite iridiscence of mother-of-pearl, the tender, delicate hues which melt into each other, glowing with soft radiance.  How different is the dull, dead surface of a piece of wax.  Yet take that dull, black wax and mould it so closely to the surface of the mother-of-pearl that it shall take every delicate marking of the shell, and when you raise it the seven-hued glory shall smile at you from the erstwhile colourless surface.  For, though it be to the naked eye imperceptible, all the surface of the mother-of-pearl is in delicate ridges and furrows, like the surface of a newly-ploughed field; and when the waves of light come dashing up against the ridged surface, they are broken like the waves on a shingly shore, and are flung backwards, so that they cross each other and the oncoming waves; and, as every ray of white light is made up of waves of seven colours, and these waves differ in length each from the others, the fairy ridges fling them backward separately, and each ray reaches the eye by itself; so that the colour of the mother-of-pearl is really the spray of the light waves, and comes from arrangement of matter once again.  Give the dull, black wax the same ridges and furrows, and its glory shall differ in nothing from that of the shell.  To apply our illustration:  as the colour belongs to one arrangement of matter and the dead surface to another, so life belongs to some arrangements of matter and is their resultant, while the resultant of other arrangements is death."[10]

The same line of reasoning naturally was applied to the existence of “spirit” in man, and it was argued that mental activity, the domain of the “spirit,” was dependent on bodily organisation.  “When the babe is born it shows no sign of mind.  For a brief space hunger and repletion, cold and warmth are its only sensations.  Slowly the specialised senses begin to function; still more slowly muscular movements, at first aimless and reflex, become co-ordinated and consciously directed.  There is no sign here of an intelligent spirit controlling a mechanism; there is every sign of a learning and developing intelligence, developing pari passu with the organism of which it is a function.  As the body grows, the mind grows with it, and the childish mind of the child develops into the hasty, quickly-judging, half-informed, unbalanced youthful mind of the youth; with maturity of years comes maturity of mind, and body and mind are vigorous and in their prime.  As old age comes on and the bodily functions decay, the mind decays also, until age passes into senility, and body and mind sink into second childhood.  Has the immortal spirit decayed with the organisation, or is it dwelling in sorrow, bound in its ’house of clay’?  If this be so, the ‘spirit’ must be unconscious, or else separate from the very individual whose essence it is supposed to be, for the old man does not suffer