They [the critics] forget that while the artist never works outside his time yet his art will go on to be merged gradually into the new art of a new age. There will be no short stop. We shall not, contrary to the expectation of these people, hear of the sudden death of Cubism, abstraction, so-called modern art.. ..if they could but realize that energy is a spiritual movement and that they must conceive of working under a law of universal aesthetic progress, as we do in science, in mathematics, in physics.