The human form must either be replaced by another object which,
whether by similarity or contrast, will strengthen the abstract
appeal, or must remain a purely non-material symbol. [Footnote:
Cf. Translator's Introduction, pp. xviii and xx.--M.T.H.S.]

Once more the metaphor of the piano. For "colour" or "form"
substitute "object." Every object has its own life and therefore
its own appeal; man is continually subject to these appeals. But
the results are often dubbed either sub--or super-conscious.
Nature, that is to say the ever-changing surroundings of man,
sets in vibration the strings of the piano (the soul) by
manipulation of the keys (the various objects with their several
appeals).

The impressions we receive, which often appear merely chaotic,
consist of three elements: the impression of the colour of the
object, of its form, and of its combined colour and form, i.e. of
the object itself.

At this point the individuality of the artist comes to the front
and disposes, as he wills, these three elements. IT IS CLEAR,
THEREFORE, THAT THE CHOICE OF OBJECT (i.e. OF ONE OF THE ELEMENTS
IN THE HARMONY OF FORM) MUST BE DECIDED ONLY BY A CORRESPONDING
VIBRATION IN THE HUMAN SOUL; AND THIS IS A THIRD GUIDING
PRINCIPLE OF THE INNER NEED.

The more abstract is form, the more clear and direct is its
appeal. In any composition the material side may be more or less
omitted in proportion as the forms used are more or less
material, and for them substituted pure abstractions, or largely