THE ALLEGED UNIVERSALITY OF MIND 369 



guilty of great cruelty when we boil our vegetables alive. Other 

 writers, influenced by the uniqueness of mind, attribute some sort 

 of mentality even to lifeless objects. Judged, however, from the 

 standpoint of evolution, there does not appear to be any warrant 

 for these fanciful speculations. As we shall see, the function of 

 mind is adaptation. It is difficult to believe that a thing so 

 clearly useful, so evidently bearing the marks of evolution, can 

 have existed prior to its usefulness. If there was any unique 



widens out to form the future body cavity. At this stage sensation and move- 

 ment appear to reside exclusively in the outer cell-layer, the ectoderm, while 

 the nutritive functions are discharged by the inner layer or entoderm." Here, 

 then, according to Wundt is a phenomenon hitherto non-existent in nature 

 i.e., living cells devoid of sensation which nevertheless perform perfectly well 

 their complex function of elaborating nutriment for themselves and other cells. 

 Loss of sensation is attributed to evolution. " At a higher level of evolution a 

 third layer of cells, the mesoderm, forms between the two. This discrimination 

 of organs is accompanied by differentiation of the elementary constituents of the 

 tissues. When the separation of ectoderm and entoderm is first accomplished 

 the cells of the former discharge the combined functions of sensation and move- 

 ment. The initial step towards the separation of these two cardinal functions is 

 apparently taken in the hydridae and medusas, where the ectoderm cells send out 

 contractile processes into the interior of the body. The sensory and motor 

 functions are still united in a single cell, but are distributed over different portions 

 of it. In the next stage the properties of sensation and contractibility pass to 

 special and spatially separated cells " (p. 36). At this stage, then, the stage 

 reached by the higher animals, Wundt supposes that sensation has departed from 

 the contractile cells. Nevertheless they contract on receipt of stimulus precisely 

 as they did before its departure. But the only evidence of sensation they ever 

 afforded was contraction. That evidence still remains and is as inconclusive in 

 the one instance as in the other. If contact alone caused an infusorian to 

 contract efficiently, the sense of touch would be as useless to it as to a muscle 

 cell. Before we attribute sensation to such low animals we should at least feel 

 sure that this wonderful product of evolution is so useful to them as to be an 

 important factor in securing survival ; that is we should feel sure that touch alone 

 without the sense of touch is not sufficient for their needs. The functions of life, 

 concentrated in a single cell in the case of the unicellular organism, are distributed 

 amongst skin, nerve, muscle, and other cells of higher types. But this separation 

 of function does not involve the corollary that no new functions (e.g. sensation) 

 have been evolved. Touch is a discriminating agency ; but discrimination does 

 not necessarily imply a mental element. Thus, apparently unaided by sensation, 

 gland cells discriminate between the substances conveyed to them by the blood. 

 It follows that an infusorian may well display tactual discrimination and yet 

 feel no sensation. Besides infusorians, many cells have cilia. In multicellular 

 organisms " all the cilia of adjoining cells do not move at once, but in regular 

 succession, the movement travelling from one cell to the other, but how this co- 

 ordination is brought about we do not know. At least, it is independent of the 

 nervous system, as ciliary movement goes on in isolated cells (i.e. cells that have 

 been scraped away) and in men it has been observed two days after death." 

 (Landois and Stirling's Physiology, vol. ii., p. 613). Here the cell, which is 

 admittedly devoid of sensation and is cut off from nerve stimuli, behaves exactly 

 like an infusorian which has been stimulated by touch. 

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