each man may only live and prosper as he exercises his natural freedom of choice, adopts values, learns how to achieve them, etc. Chapter 9, "Property and Criminality", defines a criminal as someone who uses violence against another person or their property. Rothbard raises the question: how can we know who is the rightful owner of property when we see an act of violence? For example, if we see A grabbing a watch from B, we cannot simply infer that A is a criminal and B is the innocent victim, as A may have been the rightful owner of the watch, and B may have stolen it from him. Therefore, we must investigate the particular case to determine who the legitimate property owner is. This means that we cannot simply talk about the defense of "property rights" or "private property" per se, as this may defend the property rights of a criminal aggressor. Instead, we must only speak of just or legitimate property. Rothbard also argues that the utilitarian way of looking at property rights and the free market is invalid, as it is blind to considerations of justice. Lastly, he discusses how Marxist and anarchosyndicalist arguments about the unjust ownership of property cannot be successfully countered by utilitarian arguments but must be dealt with by addressing the moral problem of the justice or injustice of various claims to property. Rothbard believes that the concept of property ownership should be treated in terms of justice and injustice rather than utilitarian terms. The basic principle of property ownership is that all resources and goods that are in a state of no-ownership belong properly to the first person who finds and transforms them into a useful good. Existing property titles must be scrutinized to ensure that they were not criminally derived. If it is not possible to identify the victim or their heirs, and the current possessor is not the criminal who stole the property, then the title should remain with the current possessor. However, if the current possessor is the criminal who stole the property, then the criminal loses the property, and it reverts to a state of no-ownership. The first person who homesteads the property then becomes its legitimate owner. Property in land Chapter 10, "The Problem of Land Theft", explains that land ownership poses unique challenges, because it is a fixed portion of the earth that endures virtually permanently.