ent of emotional changes: the ease or
difficulty of understanding producing feelings of victory or defeat
which we shall deal with later. And although the various perceptive
activities remain unnoticed in themselves (so long as easy and
uninterrupted), we become aware of a lapse, a gap, whenever our
mind's eye (if not our bodily one!) neglects to sweep from side to
side of a geometrical figure, or from centre to circumference, or
again whenever our mind's ear omits following from some particular
note to another, just as when we fall asleep for a second during a
lecture or sermon: we have, in common parlance, _missed the hang_
of some detail or passage. What we have missed, in that lapse of
attention, is a _relation,_ the length and direction of a line, or the
span of a musical interval, or, in the case of words, the references of
noun and verb, the co-ordination of tenses of a verb. And it is such
relations, more or less intricate and hierarchic, which transform what
would otherwise be meaningless juxtapositions or sequences of
sensations into the significant entities which can be remembered and
recognised even when their constituent sensations are completely
altered, namely _shapes._ To our previous formula that _beautiful_
denotes satisfaction in contemplating an aspect, we can now add that
an _aspect_ consists of sensations grouped together into _relations_
by our active, our remembering and foreseeing, perception.

CHAPTER VI

ELEMENTS OF SHAPE

LET us now examine some of these relations, not in the
genealogical or hierarchic order assigned to them by experimental
psychology, but in so far as they constitute the elements of _shape,_
and more especially as they illustrate the general principle which I
want to impress on the Reader, namely: That the perception of
Shape depends primarily upon movements which _we_ make, and
the measurements and comparisons which _we_ institute.

And first we must examine mere _extension_ as such, which
distinguishes our active dealings with visual and audible sensations
from our passive reception of the sensations of taste and smell. For
while in the case of the latter a succession of similar stimulations
affects us as "more taste of strawberry" or "more smell of rose"
when intermittent, or as a vague "there _is_ a strong or faint taste of
strawberry" and a "there is a smell of lemon flower"--when
continuous; our organ of sight being mobile, reports not "more black
on white" b