Mithraism therefore was well suited to stir and energize the individual in a time when the ancient fibre of the Romans was relaxing and when the signs of social and economic decay were evident. In the first three centuries of the Empire, as we have already had occasion to observe more than once, the loss of political power and the weakening of the satisfactions which a vigorous society can give, led men to search for other rewards and assurances than those of this world; in the mystic philosophies and religions they found their strength and hope. No oriental pagan cult had so much to offer as Mithraism. Its compelling system of ethics, the high ideal of moral purity which it inherited from its Persian source, the fraternity which its associations fostered, and the confidence which the promise of Mithras’ aid gave the individual, all combined to extend its sway to the westernmost boundaries of the Roman Empire and to maintain its power until it was forced to yield before the victorious advance of a nobler faith. The Mithraic worship was carried on in small chapels which would seldom hold as many as a hundred worshippers at once, so that when the number of devotees was considerable more than one chapel was required. No less than five have been found at Ostia, the seaport at the mouth of the Tiber, and in the capital some sixty have been discovered. These structures were generally half-subterranean, recalling the sacred cave of the Mithraic legend. Before each was a pronaos, an anteroom, from which steps led down to the chapel proper. Through the middle of this ran an aisle flanked on either side by a raised platform for the devotees. In the floor were often represented the signs of the Zodiac, which played an important part in the belief. The farther end of the chapel contained a relief which always reproduced the same scene in the type which some Pergamene sculptor had established in the Hellenistic period. The god Mithras was shown in the act of slaying the sacred bull; subordinate figures and creatures were also represented, and on some reliefs a series of scenes from the sacred legends formed a frame for the central representation. We can readily understand something of the effect produced on the mind of the neophyte when he was first introduced into the lighted chapel from the darkness without. The rows of worshippers on either side, the symbolic figures and signs, and especially the sacred relief which was doubtless brightly illuminated, must have all combined to stimulate acutely the tiro’s imagination, already stirred by his anticipations.