Writing at this time to his father-in-law, Mr. Moffat, he said, after announcing the birth of Oswell: "What you say about difference of opinion is true. In my past life, I have always managed to think for myself, and act accordingly. I have occasionally met with people who took it on themselves to act for me, and they have offered their thoughts with an emphatic 'I think'; but I have excused them on the score of being a little soft-headed in believing they could think both for me and themselves." While Kolobeng was Livingstone's headquarters, a new trouble rose upon the mission horizon. The Makololo (as Sebituane's people were called) began to practice the slave-trade. It arose simply from their desire to possess guns. For eight old muskets they had given to a neighboring tribe eight boys, that had been taken from their enemies in war, being the only article for which the guns could be got. Soon after, in a fray against another tribe, two hundred captives were taken, and, on returning, the Makololo met some Arab traders from Zanzibar, who for three muskets received about thirty of their captives. Another of the master ideas of his life now began to take hold upon Livingstone. Africa was exposed to a terrible evil through the desire of the natives to possess articles of European manufacture, and their readiness for this purpose to engage in the slave-trade. Though no African had ever been known to sell his own children into captivity, the tribes were ready enough to sell other children that had fallen into their hands by war or otherwise. But if a legitimate traffic were established through which they might obtain whatever European goods they desired in exchange for ivory and other articles of native produce, would not this frightful slave-trade be brought to an end? The idea was destined to receive many a confirmation before Livingstone drew his last breath of African air. It naturally gave a great impulse to the purpose which had already struck its roots into his soul--to find a road to the sea either on the eastern or western coast. Interests wider and grander than even the planting of mission stations on the territories of Sebituane now rose to his view. The welfare of the whole continent, both spiritual and temporal, was concerned in the success of this plan of opening new channels to the enterprise of British and other merchants, always eager to hear of new markets for their goods. By driving away the slave-trade, much would be done to prepare the way for Christian missions which could not thrive in an atmosphere of war and commotion. An idea involving issues so vast was fitted to take a right powerful hold on Livingstone's heart, and make him feel that no sacrifice could be too great to be encountered, cheerfully and patiently, for such an end. Writing to the Directors (October, 1851), he says: