ealing_.

=Examples From School-room Procedure.=--A similar relating process is
involved when the learner faces a definite school problem. When, for
instance, the pupil gains a knowledge of the sign /, he must not only
bring forward in consciousness from his former knowledge distinct ideas
of a line, of two dots, and of a certain mathematical process, but must
also associate these into a new idea, division-sign. So also a person
may know that air takes up more moisture as it becomes warmer, that the
north-east trade-winds blow over the Sahara from land areas, and that
the Sahara is situated just north of the equator. But the mind must
unify these into a single experience in order to gain a knowledge of the
condition of the rainfall in that quarter.

NATURE OF SYNTHESIS

=Deals with Former Experiences.=--This mental organizing, or unifying,
of the elements of past experiences to secure control of the new
experience, is usually spoken of as a process of synthesis. The term
synthesis, however, must be used with the same care as was noted in
regard to the term analysis. Synthesis does not mean that totally _new_
elements are being unified, but merely that whatever selected elements
of old knowledge the mind is able to read into a presented problem, are
built, or organized, into a new system; and constitute, for the time
being, one's knowledge and control of that problem. This is well
exemplified by noting the growth of a person's knowledge of any object
or topic. Thus, so long as the child is able to apperceive only the
three sides and three angles of a triangle, his idea of triangle
includes a synthesis of these. When later, through the building up of
his geometric knowledge, he is able to apperceive that the interior
angles equal two right angles, his knowledge of a triangle expands
through the synthesis of this with the former knowledge.

=All Knowledge a Synthesis.=--The fact that all knowledge is an
organization from earlier experiences becomes evident by looking at the
process from the other direction. The adult who has complete knowledge
of an orange has it as a single experience. This experience is found,
however, to represent a co-ordination of other experiences, as touch,
taste, colour, etc. Moreover, each of these separate characteristics is
an association of simpler experiences. Experiencing the touch of the
orange, for instance, is itself a complex made up of certain muscular,
touch, and temperature sensa