the homogeneous to the
heterogeneous; and a normal training system, being an objective
counterpart of this subjective process, must exhibit a like progression.
Moreover, thus interpreting it, we may see that this formula has much
wider application than at first appears. For its _rationale_ involves,
not only that we should proceed from the single to the combined in the
teaching of each branch of knowledge; but that we should do the like
with knowledge as a whole. As the mind, consisting at first of but few
active faculties, has its later-completed faculties successively brought
into play, and ultimately comes to have all its faculties in
simultaneous action; it follows that our teaching should begin with but
few subjects at once, and successively adding to these, should finally
carry on all subjects abreast. Not only in its details should education
proceed from the simple to the complex, but in its _ensemble_ also.

2. The development of the mind, as all other development, is an advance
from the indefinite to the definite. In common with the rest of the
organism, the brain reaches its finished structure only at maturity; and
in proportion as its structure is unfinished, its actions are wanting in
precision. Hence like the first movements and the first attempts at
speech, the first perceptions and thoughts are extremely vague. As from
a rudimentary eye, discerning only the difference between light and
darkness, the progress is to an eye that distinguishes kinds and
gradations of colour, and details of form, with the greatest exactness;
so, the intellect as a whole and in each faculty, beginning with the
rudest discriminations among objects and actions, advances towards
discriminations of increasing nicety and distinctness. To this general
law our educational course and methods must conform. It is not
practicable, nor would it be desirable if practicable, to put precise
ideas into the undeveloped mind. We may indeed at an early age
communicate the verbal forms in which such ideas are wrapped up; and
teachers, who habitually do this, suppose that when the verbal forms
have been correctly learnt, the ideas which should fill them have been
acquired. But a brief cross-examination of the pupil proves the
contrary. It turns out either that the words have been committed to
memory with little or no thought about their meaning, or else that the
perception of their meaning which has been gained is a very cloudy one.
Only as the mul