visual experience. The definition of space as the
possibility of motion is therefore an accurate and significant one,
since the most direct and native perception of space we can have is
the awakening of many tendencies to move our organs.

For example, if a circle is presented, the eye will fall upon its
centre, as to the centre of gravity, as it were, of the balanced
attractions of all the points; and there will be, in that position, an
indifference and sameness of sensation, in whatever direction some
accident moves the eye, that accounts very well for the emotional
quality of the circle. It is a form which, although beautiful in its
purity and simplicity, and wonderful in its continuity, lacks any
stimulating quality, and is often ugly in the arts, especially when
found in vertical surfaces where it is not always seen in perspective.
For horizontal surfaces it is better because it is there always an
ellipse to vision, and the ellipse has a less dull and stupefying
effect. The eye can move easily, organize and subordinate its parts,
and its relations to the environment are not similar in all directions.
Small circles, like buttons, are not in the same danger of becoming
ugly, because the eye considers them as points, and they diversify
and help to divide surfaces, without appearing as surfaces
themselves.

The straight line offers a curious object for analysis. It is not for
the eye a very easy form to grasp. We bend it or we leave it.
Unless it passes through the centre of vision, it is obviously a
tangent to the points which have analogous relations to that centre.
The local signs or tensions of the points in such a tangent vary in
an unseizable progression; there is violence in keeping to it, and
the effect is forced. This makes the dry and stiff quality of any long
straight line, which the skilful Greeks avoided by the curves of
their columns and entablatures, and the less economical barbarians
by a profusion of interruptions and ornaments.

The straight line, when made the direct object of attention, is, of
course, followed by the eye and not seen by the outlying parts of
the retina in one eccentric position. The same explanation is good
for this more common case, since the consciousness that the eye
travels in a straight line consists in the surviving sense of the
previous position, and in the manner in which the tensions of these
various positions overlap. If the tensions change from moment to
moment entir