We condemn theft and murder for one reason.

We condemn adultery for quite another.

We condemn the former because they are 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.