t provide
sufficiently expanded illustration to stamp these on the mind of the
learner. A shilling primer is really a more advanced book than one on a
triple scale, that should embrace the same compass of leading ideas.
As a farther condition, the work chosen should not have so much of
individuality as to fail in the character of representing the prevailing
views. The greatest authors often err on this point; and, while a work
of genius is not to be neglected, it may, for this reason, have to take
the second place in the order of study. Newton's _Principia_ could never
be a work suited for an early stage of mathematical study. Lyell's
Geology has been a landmark in the history of the subject; but it is not
cast in the form for a beginner in Geology. It is, in its whole plan,
argumentative; setting up and defending a special thesis in Geology; the
facts being arrayed with that view. Many other great works have assumed
a like form; such are Malthus on Population, Grove's Correlation of
Physical Forces, Darwin's Origin of Species. Even expressly didactic
works are often composed more to bring forward a peculiar view, than
from the desire to develop a subject in its due proportions. Locke's
Essay on the Understanding does not propose to give a methodical and
exhaustive handling of the Powers of the Mind, or even of the Intellect.
That was reserved for Reid.

The question as between old writers and new, would receive an easy
solution upon such grounds as the foregoing, were it not for the
sentiment of veneration for the old, because they are old. If an ancient
writer retains a place by virtue of surpassing merits, as against all
subsequent writers, his case is quite clear. In the nature of things,
this must be rare: if there be an example, it is Euclid; yet his
position is held only through the mutual jealousy of his modern rivals.

The only motive for commencing a study upon a very old writer is a
desire to work out a subject historically; which, in some instances may
be allowed, but not very often. In Politics, Ethics, and Rhetoric, the
plan might have its advantages; but, with this imperative condition,
that we shall follow out the development in the modern works. In
proportion as a subject assumes a scientific shape, it must carefully
define its terms, marshal its propositions in proper dependence, and
offer strict proof of all matters of fact; now, in these respects, every
known branch of knowledge has improved with th