generation to the contemplation of being, having lesser military and
retail uses also. The retail use is not required by us; but as our
guardian is to be a soldier as well as a philosopher, the military one
may be retained. And to our higher purpose no science can be better
adapted; but it must be pursued in the spirit of a philosopher, not of
a shopkeeper. It is concerned, not with visible objects, but with
abstract truth; for numbers are pure abstractions—the true
arithmetician indignantly denies that his unit is capable of division.
When you divide, he insists that you are only multiplying; his ‘one’ is
not material or resolvable into fractions, but an unvarying and
absolute equality; and this proves the purely intellectual character of
his study. Note also the great power which arithmetic has of sharpening
the wits; no other discipline is equally severe, or an equal test of
general ability, or equally improving to a stupid person.
Let our second branch of education be geometry. ‘I can easily see,’
replied Glaucon, ‘that the skill of the general will be doubled by his
knowledge of geometry.’ That is a small matter; the use of geometry, to
which I refer, is the assistance given by it in the contemplation of
the idea of good, and the compelling the mind to look at true being,
and not at generation only. Yet the present mode of pursuing these
studies, as any one who is the least of a mathematician is aware, is
mean and ridiculous; they are made to look downwards to the arts, and
not upwards to eternal existence. The geometer is always talking of
squaring, subtending, apposing, as if he had in view action; whereas
knowledge is the real object of the study. It should elevate the soul,
and create the mind of philosophy; it should raise up what has fallen
down, not to speak of lesser uses in war and military tactics, and in
the improvement of the faculties.