r than that assigned to the
other in the ratio of one to infinity. It will be my object to estimate
the relative probability of these rival estimates of the psychological
value of _x_.

Starting from _z_ as our centre, we know that this is an isolated system
of subjectivity, and hence we infer that all _y_ is composed of
analogous systems, resembling one another as to their isolation, and
differing only in their degrees of psychological value. Now this,
translated into terms of _x_ (or into terms of objectivity) means that
_z_ is an isolated system of matter in motion, and that the same has to
be said of all the constituent parts of _y_. In other words, both
subjectivity and ejectivity are only known under the condition of being
isolated from objectivity; which, obversely considered, means that the
matter in motion here concerned is temporarily separated off from the
rest of the objective world, in such wise that it forms a distinct
system of its own. If any part of the objective world rudely forces its
way within the machinery of that system, it is at the risk of
disarranging the machinery and stopping its work--as is the case when a
bullet enters the brain. Such converse as the brain normally holds with
the external world, is held through the appointed channels of the
senses, whereby appropriate causation is supplied to keep the otherwise
isolated system at work. We know, from physiological evidence, that when
such external causation is withheld, the isolated system ceases to work;
therefore, the isolation, although complete under one point of view,
under another point of view is incomplete. It is complete only in the
sense in which the isolation of a machine is complete--i. e. it is in
itself a working system, yet its working is ultimately dependent upon
causation supplied from without in certain appropriate ways. This truth
is likewise testified to on the obverse aspect of psychology. For
analysis shows that all our mental processes (however complex they may
be internally) are ultimately dependent on impressions of the external
world gained through the senses. Whether regarded objectively or
subjectively, therefore, we find that it is the business of the isolated
system to elaborate, by its internal processes, the raw materials which
are supplied to it from without. Seeing, then, that the isolation of the
system is thus only partial, we may best apply to it the term
circumscribed. Such partial isolation or circumscr