THE CONCEPTUAL WORLD 



11 



fields of energy, which we call light, radiation, etc., 

 affect the nerve-endings in the retina ; chemically 

 active particles in the atmosphere affect the nerve- 

 endings in the olfactory membranes ; and rapidly 

 repeated changes of pressure in the atmosphere 

 (sound vibrations) affect the auditory organs in the 

 internal ear, and so on. But this reception of different 

 stimuli by different receptor organs exists only in the 

 higher animal ; there are no specialised sense organs 

 in a Paramcecium, for instance, and the whole periphery 

 of the animal must receive 

 all these different kinds of 

 external stimuli at once. 

 The specialisation of its 

 receptor organs in the 

 higher animal is rather 

 the means whereby the 

 organism becomes more 

 receptive of its environ- 

 ment, than the means 

 whereby it analyses that FlG z 



environment. This ana- 

 lysis is the work of the consciousness of the 

 animal. 



Suppose that we draw a curve AB freehand with a 

 single undivided sweep of the pencil. By making a 

 certain assumption that the curve which we drew 

 was one that might be regarded as cyclical, that is, 

 might be repeated over and over again we can subject 

 it to harmonic analysis. We can decompose it into a 

 number of other curves (CD, EF, etc.), each of which 

 is a separate ' ' wave ' rising above and falling below 

 the axis OX in a symmetrical manner. If we draw 

 any vertical line MN cutting these curves, we shall 

 find that the distance between the axis OX and the 



