78 OS THE RELATION OF OPTICS TO PAINTIN&. 



I. FORM. 



The painter seeks to produce in his picture an image 

 of external objects. The first aim of our investigation 

 must be to ascertain what degree and what kind of 

 similarity he can expect to attain, and what limits are 

 assigned to him by the nature of his method. The 

 uneducated observer usually requires nothing more 

 than an illusive resemblance to nature : the more this 

 is obtained, the more does he delight in the picture. 

 An observer, on the contrary, whose taste in works of 

 art has been more finely educated, will, consciously or 

 unconsciously, require something more, and something 

 different. A faithful copy of crude Nature he will at 

 most regard as an artistic feat. To satisfy him, he 

 will need artistic selection, grouping, and even idealisa- 

 tion of the objects represented. The human figures 

 in a work of art must not be the everyday figures, 

 such as we see in photographs ; they must have ex- 

 pression, and a characteristic development, and if 

 possible beautiful forms, which have perhaps be- 

 longed to no living individuals or indeed any indi- 

 viduals which ever have existed, but only to such a 

 one as might exist, and as must exist, to produce a 



