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SCIENTIFIC THOUGHT. 



self made a very important application of it, by bringing 

 it into connection with Young's colour theory. But 

 before I refer to this, it will be well to note the different 

 lines of research which were opened out by Miiller's 

 formula, and how they have led in many ways to very 

 fruitful expansion of natural knowledge. In this respect 

 it is indeed permissible to compare Miiller's formula with 

 that of gravitation, which, as we saw above, through 

 the different ideas which it introduced, helped to guide 

 research for fully a century. Miiller in the original 

 statement of his views had made use of the term " specific 

 energy," and had applied this term to the process or 

 sense of sight : he spoke of the seeing substance or 

 apparatus of sight. Now this apparatus is a complicated 

 one, consisting mainly of three parts the external or 



edition of his great work on Physi- 

 ological Psychology in 1872. See 

 the note on p. 332, vol. i., of the 

 4th German edition (1893). Wundt 

 says (p. 331): "Historically, the 

 doctrine . . . is to be traced to the 

 fact that the philosophical founda- 

 tion of modern science, and especi- 

 ally of the science of sensation, rests 

 on Kant. In fact, that doctrine 

 is nothing else than a physiological 

 reflexion of Kant's attempt to find 

 the conditions of knowledge which 

 are given a priori, or, what was 

 mostly considered to be the same, 

 subjectively. This is very evident 

 in the case of a foremost repre- 

 sentative of that doctrine viz. , 

 Johannes Muller. " In opposition to 

 Miiller and his school, Lewes and 

 Wundt put forward a view which 

 has been termed the doctrine of 

 indifference of the function of the 

 nervous elements. The difference 

 between the two views is very clearly 

 stated in an excellent paper by E. 



Montgomery in the fifth volume of 

 'Mind' (1880): " According to the 

 doctrine of functional indifference, 

 the various qualities i.e., our well- 

 known sensations are merely due 

 to differences in the stimulating 

 rhythm, to differences, therefore, of 

 motion communicated from outside 

 to the chemically uniform nerve- 

 substance, and the whole complex 

 make-up of our consciousness is, 

 consequently, thought to result 

 from the coexistence and subse- 

 quent combination of such stim- 

 ulated motions. According to the 

 doctrine of specific energies, the 

 varieties of sensation are due to pre- 

 existing differences in the sub- 

 stratum in which they respectively 

 arise, and all their manifold combin- 

 ations to higher products are be- 

 lieved to be realised in materially 

 higher i.c, specifically pre - en- 

 dowed ranges of nervous sub- 

 stratum " (p. 4). 



