52 The Animal Mind 



11 flashes" than a steady stream. And for the Amoeba, 

 again, we must remember that even such a series would not 

 exist as such ; the perception of a series would involve the 

 revival of its past members. Each moment of conscious- 

 ness is as if there were no world beyond, before, and 

 after it. 



Another consequence of that simplicity of structure which 

 results both from the rudimentary powers of sensory dis- 

 crimination and from the absence of memory ideas in the 

 Amoeba's mind is that there can be no distinction, within 

 a given mental process, between that which is attended to 

 and that which is not attended to, between the focus and 

 the margin of consciousness. Given a consciousness which 

 at a certain moment is composed of the qualitatively differ- 

 ent elements A, B, C, and D, we can understand what is 

 meant by saying that A is attended to, is in the foreground 

 of attention, while B, C, and D remain in the background. 

 But given, on the other hand, a creature whose conscious 

 content at a certain time consists wholly of the qualitatively 

 simple experience A, it is evident that attention and in- 

 attention are meaningless terms. Different moments of 

 its consciousness may differ in intensity; but attention, 

 involving, as it does, clearness rather than intensity, arises 

 only when mental states have become complex and possess 

 detail and variety within their structure. 



