Without renouncing the support of physics, it is possible for the physiology of the senses, not only to pursue its own course of development, but also to afford to physical science itself powerful assistance. – Ernst Mach
The plain man is familiar with blindness and deafness, and knows from his everyday experience that the look of things is influenced by his senses but it never occurs to him to regard the whole world as the creation of his senses. – Ernst Mach