Throughout time painting has alternately been put to the service of the Church, the State, arms, individual patronage, scientific phenomena, anecdote and decoration … all the marvelous works that have been painted, whatever the sources of inspiration, still live for us because of absolute qualities they possess in common. The creative force and the expressiveness of painting reside materially in the colour and texture of pigments, in the possibilities of form invention and organisation, and in the flat plane on which these elements are brought into play.
As quoted in "American Modernists in Painting take the Public into their Confidence" in Current Opinion Vol LX, No. 5 (May 1916), p. 351