e whether in status where prohibition has been tried it has
failed or succeeded, and another essential fact whether under similar
conditions a combination of high license and local option has or has not
produced less drunkenness. Both are extremely complicated and difficult
facts to decide; but if clear evidence can be brought forward to
establish them, reasonable-minded people would generally hold as settled
the question of the policy which should be adopted. Similarly, an
argument for the popular election of senators would undoubtedly make
large use of the alleged fact that, in elections by the legislatures,
there has been much undue interference by special interests and rich
corporations; and the assertion of this fact would have to be supported
by evidence. If this fact were thus clearly established, it would be
recognized as a strong reason for a change in our present policy. In the
interest of clearness of thought it is worth while to remember this
distinction; for, as we shall see, it is only by so doing that we can
determine when the ordinary rules of logic do and when they do not apply
to the processes of reasoning on which argument is based. I shall speak
here, therefore, of the evidence for facts, and of the reasons for or
against a policy.

It may be said in passing that the highly complicated rules of evidence
at the common law have practically nothing to do with our present
subject, for they spring from very special conditions, and have been
molded by very special purposes. Their object is to establish, so far as
is possible, principles which will apply to all cases of a like nature;
and they therefore rule out many facts and much evidence which outside
the court we all use without hesitation in making up our minds. The jury
system has had a curious and interesting history: and judges have built
up hedges around juries which seem to the layman merely technical, and
unnecessary for the ends of justice.[14] Yet though the sweeping away of
many of these rules from time to time shows that there has been and
perhaps still is justice in this view, one must remember that the whole
common law is based on the application of principles already established
by earlier cases to new cases of like character; and that great care
must therefore be used not to establish principles which may interfere
with the even distribution of justice in the long run (see on this point
S.R. Gardiner, p. 103). Even if in single cases the r