ON THE PSYCHO-PHYSICAL VIEW OF NATURE. 519 



called the conscious automaton theory, is the central 

 conception in psychology as a natural science, or, as 

 I have termed it, of the psycho - physical view of 

 nature. It was prepared 1 by earlier thinkers, such as 

 Descartes, and, in a different form, by Spinoza, 2 and by 

 Leibniz's doctrine of pre-established harmony. 3 It has 

 been strengthened by the physiological theory of reflex 

 action, 4 and, independently, by psycho -physics in the 

 narrower sense of the word, as founded by Weber and 

 Fechner. But the possibilities of the automaton theory 

 were not scientifically tested till towards the end of 

 the nineteenth century. In this country, two thinkers 



1 The doctrine of psycho-physical 

 parallelism and its historical genesis 

 is given by Huxley in his address 

 before the British Association Meet- 

 ing at Belfast in 1874, " On the 

 Hypothesis that Animals are Auto- 

 mata, and its History," in which he 

 goes back to Descartes and Charles 

 Bonnet. A good account of the 

 theory is also given by Prof. Wm. 

 James in the 5th chapter of his 

 ' Principles of Psychology ' ; and it 

 is fully discussed by Prof. James 

 Ward in his Gifforcl lectures, 

 ' Naturalism and Agnosticism,' vol. 

 ii. pt. iii. 



2 The passage from Spinoza which 

 is constantly quoted, and, as Prof. 

 Ward says, usually in ignorance of 

 the context, is in 'Ethica,' part ii. 

 prop. 7 : " Ordo et connexio ide- 

 arum idem est ac ordo et connexio 

 rerum." 



:i Leibniz, as Huxley (loc. cit. ) 

 tells us, also invented the term 

 " automate spirituel " and appplied 

 it to man. 



* Du Bois - Reymond, in his 

 "Eloge" of Johannes Muller, has 

 shown that the principle of reflex 

 action dates back to Descartes, 

 who also introduced the term re- 



flex. Next in time came Willis 

 ('De motu musculari,' Amsterdam, 

 1682). The subject seems to have 

 been overlooked to such an extent, 

 that Prochaska (1784) got for a 

 long time the credit of having 

 established the notion of reflex 

 action, and even his work had to 

 be rediscovered by Eduard Weber 

 (1846), after the principle of the 

 transition of a reaction from the 

 afferent to the efferent nerves in 

 the central organs had been prom- 

 inently put forward by Legallois 

 (1811), Marshall Hall (1835), and 

 Johannes Muller (1835). In more 

 recent times, Prof. Pfliiger's " Laws 

 of Reflex Action," and his and G. 

 H. Lewes's theory of the presence 

 of consciousness in the spinal cord, 

 have formed the subject of much 

 discussion and much experimental 

 work. A good historical account 

 will be found in the 13th Le^on 

 of M. Ch. Richet's ' Physiologic 

 des Muscles et des Nerfs' (Paris, 

 1882), and a discussion of the whole 

 subject in Prof. Wundt's 'Physi- 

 ologische Psychologie, ' ch. xxi., 

 where especially the difference be- 

 tween automatic and reflex move- 

 ment is brought out. 



