Carus, The Seat of Consciousness. 177 



as it were, store-houses of innumerable memories systematically 

 registered according to the laws of association and psychical dy- 

 namics. Sight-impressions are conducted from the eye along the 

 optic nerve, sounds from the ear along the acoustic nerve; in short, 

 all the sensations start from their sense-organs and, naturally 

 following the traces of those former impressions whose forms 

 they fit best, pass along through an intermediate station to their 

 various termini in the cortex. There they are fused with mem- 

 ories of the same kind, forming complicated brain-structures 

 which Galton defined as composite images. In this way the 

 various sense-impressions build up a system of composite mem- 

 ories, which, together with their appropriate reactions, form the 

 frame-work of our soul. 



Now, we assume all nervous activity to be sentient. The 

 spinal cord of the frog which has been severed from the frog's 

 brain must, so long as it properly reacts upon a stimulus, be 

 irritable ; yet the feeling that we suppose to take place in the 

 spinal ganglion is not reported at the headquarters of the brain, 

 for it can not be projected higher and remains unconscious. 

 The negative part of the popular conception is perfectly correct : 

 feelings which do not rise into the highest sphere of nervous ac- 

 tivity cannot become conscious ; but there are many nervous 

 activities which, although they have their seat in the hemis- 

 pheres, remain as much unconscious as those that take place in 

 the lower systems of projection. Think of a piano-player. His 

 knowledge of the notes and of the keys is registered in the 

 acoustic centre of the hemispheres; and yet when he plays a 

 piece that he has learned by heart a glance at the notes is suffi- 

 cient to start a great number of complex and intelligent motions 

 without engaging his consciousness. There is always a great 

 amount of unconscious cerebration whenever we write, or read, 

 or think. We concentrate our conscious efforts upon those points 

 which are new and require extraordinary attention, while all 

 those performances to which we have grown accustomed by 

 long practice are attended to with unconscious ease. Indeed, 

 we- are constantly carried on the pinions of unconscious 

 thought which works with machine-like accuracy and perfect 



