concept is familiar in pictorial composition and to some extent
also in music and poetry, but here first appears as grounded in
the very demand for the union of repose with activity.

Moreover, this requirement, which we have derived from the
logical concepts of unity and totality, as translated into
psychological terms, receives confirmation from the nature of
organic life. It was the perfect moment that we sought, and we
found it in the immediate experience of unity and self-completeness;
and unity for a living being CAN only be equilibrium. Now it
appears that an authoritative definition of the general nature of
an organism makes it "so built, whether on mechanical principles
or not, that every deviation from the equilibrium point sets up
a tendency to return to it."<1> Equilibrium, in greater or less
excursions from the centre, is thus the ultimate nature of
organic life. The perfect equilibrium, that is, equilibrium with
heightened tone, will then give the perfect moment.

<1> L.T. Hobhouse, _Mind in Evolution_.

The further steps of aesthetics are then toward analysis of the
psychological effect of all the elements which enter into a
work of art, with reference to their effect in producing
stimulation or repose. What colors, forms, tones, emotions,
ideas, favorably stimulate? What combinations of these bring
to repose? All the modern studies in so-called physiological
aesthetics, into the emotional and other--especially motor--
effects of color, tone-sensation, melodic sequence, simple
forms, etc., find here there proper place.