incompatible with any form of happiness. We condemn the latter because
it is the supposed destruction of one particular form; or the
substitution, rather, of a form supposed to be less complete, for
another form supposed to be more complete. If the '_highest good_,' if
the best kind of happiness, be the end we are in search of, the truths
of sociology will help us but a very short way towards it. By the
practice of '_band-work_' alone we shall never learn to construct a
'_true_ Civitas Dei.' Band-work with the same perfection may be
practised for opposite ends. Send an army in a just war or an unjust
one, in either case it will need the same discipline. There must be
order amongst thieves, as well as amongst honest men. There can be an
orderly brothel as well as an orderly nunnery, and all order rests on
co-operation. We presume co-operation. We require an end for which to
co-operate.

I have already compared the science of sociology to that of medicine;
and the comparison will again be a very instructive one. The aim of both
sciences is to produce health; and the relation of health to happiness
is in both cases the same. It is an important condition of the full
enjoyment of anything: but it will by no means of itself give or guide
us to the best thing. A man may be in excellent health, and yet, if he
be prudent, be leading a degrading life. So, too, may a society. The
Cities of the Plain may, for all we know to the contrary, have been in
excellent social health; indeed, there is every reason to believe they
were. They were, apparently, to a high degree strong and prosperous;
and the sort of happiness that their citizens set most store by was only
too generally attainable. There were not ten men to be found in them by
whom the _highest good_ had not been realised.

There are, however, two suppositions, on which the general good, or the