 Soto, who also participated in the debate in Valladolid, said that the ius gentium was a universally applicable form of positive human law, which was created by applying reason to natural principles. This law governed trade, exchange of envoys, and even slavery, if it spared lives during war. It also included respect for property, even of non-Christians, to avoid squabbles over possessions. Nor was conversion a just reason for going to war and enslaving conquered peoples.