120 ANIMAL BEHAVIOUR 



passive contemplation of the events that occur in the environment. 

 And we know, of course, that purposeful behaviour, involving 

 the whole sensori-motor system, may proceed without sensation 

 passing into consciousness. 



43/. The Unities of Sensation. Since there are very many 

 kinds of receptors functioning at the same time it follows that 

 we generally have a multiplicity of sensations all more or less 

 passing into consciousness. Such complexes are integrated into 

 unities and these are what the animal reacts to in its behaviour. 

 A complex of sensations acquires significance and is individualized 

 as the antecedent to bodily action of some kind. Thus in crossing 

 a street in busy traffic the visual and auditory organs must transmit 

 innumerable impulses to the nerve-centres, but only a few of 

 these can receive, or indeed demand, attention and response in 

 action. The visual impressions of several vehicles ; their 

 proximities, directions of movement and velocities ; the sounds 

 of motor horns ; the movements of the policeman on point duty — 

 these sense-impressions are integrated as sensational unity which 

 is then attended to while experience suggests the appropriate 

 bodily response. 



43^. The Intuition of Duration. What we call duration 

 (or *' time ") is the consciousness we have of the passage of nature 

 (see again, Section 2). A purely physical system of things passes 

 in that its available energy (and thus its inherent physical causality) 

 becomes less and less as the system tends towards stability. But 

 the organism resists the passage to physical stability and it remains 

 a permanent centre of causality — since it is not only an individual 

 thing but a succession of living things constituting a race. The 

 consciousness of this resistance to physical degradation is our 

 intuition of duration. It is cumulative in that the phases of the 

 passage of nature persist as memories, as motor habits and 

 as instincts. It is cumulative in that the present phase is not 

 merely the superposition of the past phases but is an integration, 

 and always something new, and it is in this sense that Bergson 

 speaks of duration as creative. Nothing can be more immediate, 

 or intuitive, than the duration of the animal since, being the 

 consciousness of that which distinguishes the animate system of 

 things from the inanimate one, it is life itself. 



'* Time " punctuates duration by referring the organic phases 



