SUGGESTIBILITY AND KINDRED PHENOMENA. 195 



one cortical area to another ; meeting, they re-enforce or destroy 

 one another; impinging upon a cell system which was in com- 

 parative quiet, they rouse it to activity, and are themselves modi- 

 fied by the pulses which it gives forth. At every second this 

 mass of activities is receiving from the myriads of nerves that 

 reach out to the eye, ear, skin, and other sensitive portions of the 

 body countless other pulses of the same character, but initiated 

 by the physical stimuli of the external world or by the chemical 

 changes of the body. These pulses are not accompanied by con- 

 sciousness, but when they reach the cortex they merge into the 

 complex mass there existing and contribute their share toward 

 the character of the total conscious state. And in the last place, 

 the activities disengaged within the cortex are ever discharging 

 downward through the outgoing channels into the co-ordinating 

 mechanism at the base of the brain. This controls the sys- 

 tems of muscular contractions needed for the performance of our 

 bodily movements much as the " combination stops " of an organ 

 control the systems of pipes needed to produce any given timbre 

 effect. 



Thus the consciousness that you and I at any moment experi- 

 ence depends for its character upon the constitution of a system 

 of activities as definite and determinate as any known to the 

 physicist, although so complex that we can never hope to unravel 

 it. To compare the complex with the simple, we have all seen 

 the play of color upon the surface of a soap bubble. These colors 

 depend for their character upon the constitution of a system of 

 forces far more simple than that which underlies the human con- 

 sciousness. They are due to the interference of waves of ether 

 reflected from the inner and outer surfaces of the film ; they de- 

 pend, therefore, upon the angle of incidence and the thickness of 

 the film. These two conditions again depend upon the tenacity 

 of the film, the difference between the pressure within and that 

 without the bubble, the action of air currents, the muscular tremor 

 of the hand that holds the pipe, the action of gravity, etc. If any 

 one of these conditions be in any way altered, some change will 

 be made in the tint. This throws light upon one of the reasons 

 why psychology lags so far behind the other sciences. Suppose 

 the physicist should select that one square inch on the surface of 

 the bubble where the colors were brightest, and should endeavor 

 to formulate for each, in terms of the others, the laws of existence 

 and sequence, ignoring the while the system of forces upon which 

 those colors depend : however painstaking his efforts, they would 

 meet with little success, and this has been the fate of the psycholo- 

 gist. Too often he has confined his attention to that portion of 

 consciousness which was brightest, or for some other reason the 

 most interesting, while if he had but looked into the marginal or 



