442 PHYSIOLOGY CHAP. 



effects of a Ideological character, without active intervention oi' 

 the higher cerebral centres i.e. without transformation into 

 perception, representation, and volition that we term unconscious 

 in the widest and most general sense of the word. 



As conscious psychical processes may become unconscious 

 by exercise and habit, so, evidently, many unconscious psychical 

 processes may become conscious when we direct our attention to 

 them. It is more remarkable that, independently of the attention, 

 an unconscious operation may unexpectedly lead to a conscious 

 intellectual result. 



It is sometimes impossible to recall the name of a person, 

 however strenuously we flog our memory ; 1 ut if we cease to 

 think about it, and turn to other things, the name sought in 

 vain may presently be remembered. Again, the utmost effort of 

 intelligence may fail to reveal to us the relation and interdepend- 

 ence of certain observed phenomena or the solution of a long- 

 considered scientific problem: alter giving up the attempt and 

 turning our thoughts to another subject, it sometimes happens 

 that the solution vainly sought presents itself clearly and 

 convincingly on the mental horizon, without conscious effort. 



The history of science is full of such examples : the discovery 

 of the principle of the rotating magnetic field by Galileo Ferraris 

 is a striking proof of this. " One evening in August 1885 " 

 (writes his biographer, 11. Arno) "he went as usual for a walk, 

 wandering alone in the neighbourhood of the Cernaja barracks 

 in Turin. He was musing as he went, in a brown study. And 

 giving rein to the natural sequence of his thoughts he began to 

 reflect on the analogy of optical and electro-magnetic phenomena, 

 and on the origin of light electrically and circularly polarised, 

 which depends on the combination of two simple oscillatory 

 movements of the ether. A flash of genius arrested him ; and he 

 asked himself whether a similar effect could not be brought about 

 by substituting the variations of two superposed magnetic fields 

 for the two component oscillations." 



These are typical examples of a direct transformation of 

 conscious into unconscious neural processes, and then of the 

 latter into the former without the intervention of attention. 

 " Unconscious activity," as Hoffding justly remarks, " has effected 

 that which direct and assiduous mental labour could never have 

 accomplished." In these cases, conscious initial work is the first 

 condition of the effect ; the subsequent unconscious work is the 

 means that consummates the action, by which the final result 

 desired is attained in a well-defined and clearly conscious form. 



Accordingly, it cannot be denied that unconscious neural 

 processes have the same character as conscious processes, and 

 that the range of psychical life is not confined to the latter, 

 which form the content of the empirical or sensorial self, but 



