Thirdly we must bear in mind that the world was cosmopolitan. For centuries traders had carried not only wares but ideas from one part of the ancient world to another, slaves had done their part, which was not small, since many of them were educated; and from the time of Augustus the soldiers drawn from every province of the Empire exerted a great influence in breaking down the barriers between the nations. For the idea of a cosmopolitan world Stoicism had furnished a philosophic basis; the actuality was realized in large measure by the natural developments under Roman imperial rule. Separate nations had ceased to exist; and in the universal levelling which a growing autocracy produced, the differences between citizens, provincials, and slaves were diminished and an approach was made to a cosmopolitan equality. Furthermore the Roman world of the first three centuries was virtually a world of peace. Merchants and traders, tourists and missionaries moved freely from one end of the Empire to the other. The value of this Roman peace was recognized by the Christians; near the end of the second century the Christian writer Irenaeus declared: “The Romans have given the world peace and we travel without fear along the roads and across the sea wherever we will.”[301] The world was also one of religious unrest and inquiry. The traditional religions and the inherited forms of religious expression had in large part failed. There was, as has been said in an earlier lecture, a sense of weariness and dissatisfaction which showed itself in the large resort of all classes to Stoic philosophy, in the devotion among the cultured to the mystic philosophies, in conversions to Judaism, and later in the ready reception of oriental religions, including Christianity. We have already seen how both philosophy and mysticism recognized that men had a sense of moral guilt and were conscious of an estrangement from God through sin, from which they desired to secure purification, that is, to attain freedom from the common lot of the bondage of wickedness. Philosophy and mysticism also agreed in holding that the means at man’s disposal were not sufficient to accomplish his release, that the reason and the will unaided could not free him, and that therefore external help was necessary—that an act of grace made known by a divine revelation was required. This escape from sin, this freeing of man’s spirit, for which they longed, was regarded as a reunion with God, which gave the promise of security and salvation here and hereafter, and which thereby answered man’s hope for an unbroken and a perfected existence. It was into a world of such a nature and with such religious thoughts as these that Christianity entered.