When Christianity arrived on the scene, Rome had already extended its power around the Mediterranean world, and had begun its transformation into a monarchical empire. The city of Rome began to decline in the third century as the empire faced economic challenges. The persecution by Decius issued from a sense that the gods who had made Rome great had to be placated if that greatness were to be maintained. Philosophical schools were a major factor in Roman Christianity, despite the lack of traditional basis. Philosophy is mentioned once in the New Testament as 'hollow speculations', and pagans initially dismissed Christian claims to be lovers of wisdom by calling their religion a superstition. Crucial steps in the shaping of inner-Christian scholarly discourse, together with the development of the categories of 'heresy' and 'orthodoxy', were taken by Justin's school. Justin, together with his pupil, Tatian, and Tatian's pupil, Rhodon, engaged in critique of pagan and Jewish teachers and philosophers.