how then can a mere collection of laws teach a
man the science of legislation, or make him able to judge which of them are the best?
[
21]
We do not see men becoming expert physicians from a
study of medical handbooks. Yet medical writers attempt to describe not only general
courses of treatment, but also methods of cure and modes of treatment for particular sorts
of patients, classified according to their various habits of body; and their treatises
appear to be of value for men who have had practical experience, though they are useless
for the novice. Very possibly therefore collections of laws and constitutions may be
serviceable to students capable of studying them critically, and judging what measures are
valuable or the reverse, and what kind of institutions are suited to what national
characteristics. But those who peruse such compilations without possessing a trained
faculty cannot be capable of judging them correctly, unless they do so by instinct, though
they may very likely sharpen their political intelligence.
[
22]
As then the question of legislation has been left uninvestigated by previous thinkers, it
will perhaps be well if we consider it for ourselves, together with the whole question of
the constitution of the State, in order to complete as far as possible our philosophy of
human affairs.
[23]
We1 will begin then by attempting
a review of any pronouncements of value contributed by our predecessors in this or that
branch of the subject; and then on the basis of our collection of constitutions2 we will
consider what institutions are preservative and what destructive of states in general, and
of the different forms of constitution in particular, and what are the reasons which cause
some states to be well governed and others the
contrary. For after studying these questions we shall perhaps be in a better position to
discern what is the best constitution absolutely, and what are the best regulations, laws,
and customs for any given form of constitution. Let us then begin our discussion.