There is no consensus on what a slave was or on how the institution of slavery should be defined. Nevertheless, there is general agreement among historians, anthropologists, economists, sociologists, and others who study slavery that most of the following characteristics should be present in order to term a person a slave. The slave was a species of property; thus, he belonged to someone else. In some societies slaves were considered movable property, in others immovable property, like real estate. They were objects of the law, not its subjects. Thus, like an ox or an ax, the slave was not ordinarily held responsible for what he did. He was not personally liable for torts or contracts. The slave usually had few rights and always fewer than his owner, but there were not many societies in which he had absolutely none. As there are limits in most societies on the extent to which animals may be abused, so there were limits in most societies on how much a slave could be abused. The slave