he proper kind, and in proper
proportions;--keeping the thinking powers constantly in healthful
exercise, by giving as many ideas as the mind can reiterate without
fatigue; but carefully avoiding all hurry or force, seeing that the
powers of the mind are greatly weakened and injured by a multiplicity of
objects, particularly when they are presented so rapidly, that the
thoughts have not time to settle upon them, nor the mind to reiterate
the ideas which they suggest.

CHAP. VI.

_On the Application of Knowledge by the Principle of Association, or
Grouping._

Another principle which exhibits itself in the acquisition of knowledge
by Nature's pupils, is that of "grouping," or associating objects
together, after they are individually known. A child, or even an infant,
who is frightened, or alarmed, or who suffers any severe injury,
remembers the several circumstances, and has the place, the persons, and
the things connected with the event, all associated together, and
grouped into one scene or picture on the memory. These objects may have
been numerous; but by the operation of this principle, they have all
been apprehended, and united so powerfully with each other, that no
future effort of the child can either separate or obliterate any portion
of them; and so comprehensive, that the recollection of any one of the
circumstances instantly recalls all the others.

These groupings in the mind of a child, formed chiefly by means of the
imagination, are almost wholly compounded of sensible objects; and the
only necessary prerequisite for their formation appears to be a
knowledge of the individual elements of which they are to be composed.
If an unknown object be presented to the mind in connection with the
others that are known, it is generally excluded, and the things
previously known retained. For example, in the case supposed above, of
an accident occurring to a child, there would be thousands of objects
present, and all cognisable by the senses; but not one of all these that
were unknown, that is, that had not previously undergone the process of
individuation, is found to form part of the remembered group.

There is another circumstance connected with the operation of this
principle in the young, which is of importance. Almost the whole of a
child's knowledge is composed of these groupings. Before the
developement of the reasoning powers, by which the individual is enabled
to _classify_ the elements of his kno