and an important step forward was achieved--this step forward
has, however, had the effect of limiting the possibilities of
painting to one definite piece of canvas, and this limitation has
not only introduced a very material element into painting, but
has seriously lessened its possibilities.

Any attempt to free painting from this material limitation
together with the striving after a new form of composition must
concern itself first of all with the destruction of this theory
of one single surface--attempts must be made to bring the picture
on to some ideal plane which shall be expressed in terms of the
material plane of the canvas. [Footnote: Compare the article by
Le Fauconnier in the catalogue of the second exhibition of the
Neue Kunstlervereinigung, Munich, 1910-11.] There has arisen out
of the composition in flat triangles a composition with plastic
three-dimensional triangles, that is to say with pyramids; and
that is Cubism. But there has arisen here also the tendency to
inertia, to a concentration on this form for its own sake, and
consequently once more to an impoverishment of possibility. But
that is the unavoidable result of the external application of an
inner principle.

A further point of great importance must not be forgotten. There
are other means of using the material plane as a space of three
dimensions in order to create an ideal plane. The thinness or
thickness of a line, the placing of the form on the surface, the
overlaying of one form on another may be quoted as examples of
artistic means that may be employed. Similar possibilities are
offered by colour which, when rightly used, can advance or
retreat, and can make of the picture a living thing, and so