The question of realism

Until we have settled the question of whether moral beliefs necessarily have motivational force, for example, we are in no position to say whether it is a point in favor of a given account of our moral practice that it endows them with such a force; and until we have decided whether mathematical beliefs can be known a priori, we will be unable to say whether it is a point in favor of an account of our mathematical practice that it allows them to have such a status. A realist or antirealist conclusion therefore represents the terminus of philosophical inquiry into a given area rather than its starting point; and so it is hardly surprising that such slight progress has been made within realist metaphysics, even by comparison with other branches of philosophy.