open its inward parts and display the very heart of its
principles, and to show forth the roots from which it buds and
flourishes, and that the emanation of its springs may be seen of
all men; for thus from the cognate and harmonious light of the
truth of conclusion to principles, the whole body of science
will be full of light, having no part dark. But laws, on the
contrary, since they are only human enactments for the regulation
of social life, or the yokes of princes thrown over the necks of
their subjects, refuse to be brought to the standard of
synteresis, the origin of equity, because they feel that they
possess more of arbitrary will than rational judgment. Wherefore
the judgment of the wise for the most part is that the causes of
laws are not a fit subject of discussion. In truth, many laws
acquire force by mere custom, not by syllogistic necessity, like
the arts: as Aristotle, the Phoebus of the Schools, urges in the
second book of the Politics, where he confutes the policy of
Hippodamus, which holds out rewards to the inventors of new laws,
because to abrogate old laws and establish new ones is to weaken
the force of those which exist. For whatever receives its
stability from use alone must necessarily be brought to nought by
disuse.

From which it is seen clearly enough, that as laws are neither
arts nor sciences, so books of law cannot properly be called
books of art or science. Nor is this faculty which we may call
by a special term geologia, or the earthly science, to be
properly numbered among the sciences. Now the books of the
liberal arts are so useful to the divine writings, that without
their aid the intellect would vainly aspire to understand them.