Physics is experience, arranged in economical order. – 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
If our dreams were more regular, more connected, more stable, they would also have more practical importance for us. – Ernst Mach
The presentations and conceptions of the average man of the world are formed and dominated, not by the full and pure desire for knowledge as an end in itself, but by the struggle to adapt himself favourably to the conditions of life. – Ernst Mach