 For Christians, it was clear Church doctrine that the world has a beginning, and in the thirteenth-century Latin universities some theologians tried to use Philoponian arguments to claim this position could be demonstrated. Like Maimonides, Boethius of Dacia (Boethius of Dacia [1987]), the leading Arts Master in the 1260s–70s, did not accept that either these arguments, or those for the eternity of the world, are demonstrative. But he also thought that a practitioner of Aristotelian natural science (one of the roles of an Arts Master) had to go further and actually deny the world has a beginning, because natural science is founded on the principle that every change requires a preceding change. In order to save Arts Masters from heresy, Boethius advocates a limited relativism. When natural scientists state that the world has no beginning, they are saying that the world has no beginning according to the principles of natural science, a position in harmony with the true Christian doctrine, according to which it does have a beginning.