The Christians may, with far more force, ask the positivists how they expect to enjoy themselves on earth.

For the Christians' heaven being _ex hypothesi_ an unknown world, they do not stultify their expectations from being unable to describe them.

On the contrary it is a part of their faith that they are indescribable.

But the positivists' heaven is altogether in this world; and no mystical faith has any place in their system.

In this case, therefore, whatever we may think of the other, it is plain that the tests in question are altogether complete and final.