"It can be noted that Shaka was challenged to create the heavy stabbing when he realized that the throwing spear broke when used as a stabbing weapon. More important still, what Shaka came up with depended upon the collective effort of the Ama-Zulu. Shaka could ask that a better assegai be forged, because the Ama-Ngoni had been working iron for a long time, and specialist black-smiths had arisen within certain clans. It was a tribute to the organizational and agricultural capacity of the society as a whole that it could feed and maintain a standing army of thirty thousand men, re-equip them with iron weapons, and issue each soldier with the full-length Zulu shield made from cattle hide. Because the scientific basis and experimental preconditions were lacking in Zulu society, Shaka could not have devised a firearm—no matter how much genius he possessed. But, he could get his people to forge better weapons, as explained above; and he found them receptive to better selective breeding practices when he set up special royal herds, because the people already had a vast fund of empirical knowledge about cattle and a love of the cattle-herding profession."