ul' because it enables us to get quickly and
easily at the evidence, to take effective securities for its
truthfulness, to estimate its relevance and importance, to leave the
decision to the most qualified persons, and so forth. These points,
again, can only be decided by a careful appeal to experience, and by
endeavouring to understand the ordinary play of 'motives' and
'sanctions.' What generally makes a man lie, and how is lying to be made
unpleasant? By rigorously fixing our minds at every point on such
issues, we find that many questions admit of very plain answers, and are
surprised to discover what a mass of obscurity has been dispelled. It
is, however, true that although the value of the method can hardly be
denied unless we deny the value of all experience and common sense, we
may dispute the degree in which it confirms the general principle. Every
step seems to Bentham to reflect additional light upon his primary
axiom. Yet it is possible to hold that witnesses should be encouraged to
speak the truth, and that experience may help us to discover the best
means to that end without, therefore, admitting the unique validity of
the 'greatest happiness' principle. That principle, so far as true, may
be itself a deduction from some higher principle; and no philosopher of
any school would deny that 'utility' should be in some way consulted by
the legislator.

The book illustrates the next critical point in Bentham's system--the
transition from law to politics. He was writing the book at the period
when the failure of the Panopticon was calling his attention to the
wickedness of George III. and Lord Eldon, and when the English demand
for parliamentary reform was reviving and supplying him with a
sympathetic audience. Now, in examining the theory of evidence upon the
plan described, Bentham found himself at every stage in conflict with
the existing system, or rather the existing chaos of unintelligible
rules. English lawyers, he discovered, had worked out a system of rules
for excluding evidence. Sometimes the cause was pure indolence. 'This
man, were I to hear him,' says the English judge, 'would come out with a
parcel of lies. It would be a plague to hear him: I have heard enough
already; shut the door in his face.'[420] But, as Bentham shows with
elaborate detail, a reason for suspecting evidence is not a reason for
excluding it. A convicted perjurer gives evidence, and has a pecuniary
interest in the result. That is