EPILOGUE 



This is the story of the development of the eye from the primitive undiffe- 

 rentiated protoplasm of the simplest protozoon to become the most highly efficient 

 sensory mechanism in the animal kingdom in the eyes of Birds. It is the story 

 of the development of the sense of vision from an automatic response, associated 

 at some stage with a vague awareness, to the capacity to he enraptured by a 

 sunset or a rainbow or to create a thing of beauty. The first story is factual; 

 the second specidative. 



The subject of the second is fraught withdiffictdties sogreat as to make a fined 

 solution impossible. In the physiccd world matericd things are incomprehensible 

 to each other and can he analysed only on a higher level by the senses; the sense- 

 organs know nothing of each other for sensations can he cnialysed only by percep- 

 tions; we have no access to a platform wherefrom to look down upon perceptions 

 and subject them to analysis. It follows that our consciousness is to us un- 

 knoivable and ivill probably remain so — until or unless we acquire other and 

 higher faculties. And if we, in our wordy thinking, cannot mutucdly 

 compare the symbolic representation that each of us creates perceptually of the 

 outside world, how much more difficult to ancdyse what the animal world in its 

 ivordless thinking makes of it. 



A hypothesis might run like this. There are three stages in the evolution 

 of visio7i. It started as a motor taxis, appearing initicdly in the simplest 

 unicellular organisms as an automatic response which eventually became more 

 plastic to reach its culmination in the homing bird; as such it need not enter 

 consciousness. From this emerged perceptual vision, a pragmatic sense, 

 essentially a passive registration of objects in the outside world, serving priynarily 

 the biological needs of hunger, fear or sex. Initially a minor, it eventually 

 became a major determinant of conduct. Dependent on a centred nervous 

 organization to create its symbolism , it started in worms and reached its highest 

 level in man. From this emerged imaginative vision with its aesthetic and 

 creative qualities, with its inquisitive, exploratory drive, seeing beauty. It 

 depended on the almost explosive develojjment of the frontal brain in the highest 

 Primates. It first appeared, presumably, during the ape-man s arboreal adven- 

 ture and certainly is present in the chimpanzee ; it was well established when 

 modern man migrated northwards folloiving the melting of the ice 20,000 years 

 ago to replace his Neanderthal predecessors and establish the Aurignacian and 

 Magdalenian cave-civilizations in south-west Europe, and reaches its greatest 

 development, jjerhaps, in the human mind relieved of the chemical servitude of 

 iyihihitions, as by mescalin. 



It is a fascinating story extending back to where life started, a story mostly 

 of steady progress, now in this direction, now in that, as one expedient after 

 another ivas tried, this one to be discarded, that to be perfected. It is a long 

 story, and in this Volume it can oidy be sketchily told. 



In the volumes of this series which follow we will discuss in more detail 

 the visual apparatus of man — its structure, its development, its function, and 

 the effects upon it of disease and injury. 



S.O.— VOL. I. 753 48 



