 The conversion of the native peoples, however, did not provide an unproblematic justification for the project of overseas conquest. The Spanish conquest of the Americas was taking place during a period of reform when humanist scholars within the Church were increasingly influenced by the natural law theories of theologians such as St. Thomas Aquinas. According to Pope Innocent IV, war could not be waged against infidels and they could not be deprived of their property simply because of their non-belief. Under the influence of Thomism, Innocent IV concluded that force was legitimate only in cases where infidels violated natural law. Nonbelievers had legitimate dominion over themselves and their property, but this dominion was abrogated if they proved incapable of governing themselves according to principles that every reasonable person would recognize. The Spanish quickly concluded that the habits of the native Americans, from nakedness to unwillingness to labor to alleged cannibalism, clearly demonstrated their inability to recognize natural law. This account of native customs was used to legitimize the enslavement of the Indians, which the Spanish colonists insisted was the only way to teach them civilization and introduce them to Christianity.