Perhaps the same vessel or fleet which carried him to the islands, with orders intended to advance his influence, would bear fellow-passengers with documents or means to thwart all his reinforced mission. He left Spain again in 1520, only to cast himself on a new sea of troubles soon inducing him to return. His sixth voyage carried him this time to the mainland in Mexico, in 1537. He was in Spain once more in 1539. While waiting here for the return of the Emperor, he composed six of his many essays upon his one unchanging theme, all glowing with his righteous indignation, and proffering wise and plain advice to the monarch. Yet again he crossed the now familiar ocean to America, in 1544, it being his seventh western voyage, and returned for the seventh and last time to Spain in 1547. Here were fourteen sea-voyages, with their perils, privations, and lack of the common appliances and comforts shared in these days by the rudest mariners. These voyages were interspersed by countless trips and ventures amid the western islands and the main, involving twofold, and a larger variety of harassments and risks, with quakings, hurricanes, and reefs, exposures in open skiffs, and the privilege of making one’s own charts. But one year short of fifty in the count out of his lengthened life were spent by this man of noble ardor, of dauntless soul, and of loving heart in a cause which never brought to him the joy of an accomplished aim. Las Casas shared, with a few other men of the most fervent and self-sacrificing religious zeal, an experience of the deepest inward conviction, following upon, not originally prompting to, the full consecration of his life to his devoutest aim. Though he had been ordained to the priesthood in 1510, he was afterward made to realize that he had not then been the subject of that profound experience known in the formulas of piety as true conversion. He dates this personal experience, carrying him to a deeper devotional consciousness than he had previously realized, to the influence over him of a faithful lay friend, Pedro de la Renteria, with whom he became intimate in 1514. To the devout conversation, advice, and example of this intimate companion he ascribed his better-informed apprehension of the radical influences which wrought out the whole system of wrong inflicted upon the natives. Las Casas himself, like all the other Spaniards, had a company of Indian servants, who were in effect slaves; and he put them to work, the benefit of which accrued to himself. A form of servitude which exceeded all the conditions of plantation slavery had been instituted by Columbus under the system of so-called _repartimientos_. It was founded on the assumption that the Spanish monarch had an absolute proprietary right over the natives, and could make disposals and allotments of their services to his Christian subjects, the numbers being proportioned to the rank, standing, and means of individuals,