Robert Nozick claims that we should apply the principle of initial acquisitions of just holdings in historical instances. This book shows that the proviso for the principle of initial acquisitions of just holdings which Nozick suggests, cannot be an action-guiding principle at the stage of Homo habilis and Homo rudolfensis and this alters the claim that the Entitlement Theory is a historical principle . Considering this central claim, the study here explores the social and cognitive capabilities of these early hominids, in order to construct the historical instance of early hominid social life. Secondly, it gives account of their mindreading ability based on mental simulation. By means of these, this book shows that Homo habilis and Homo rudolfensis were cognitively incapable of being guided by the Nozickean Proviso. Thus, this issue puts limits on the accessibility of the Entitlement Theory to all historical instances. This study should help academics whose main field is libertarianism and political philosophy in general. Scholars of political philosophy can find the new hybrid approach to political philosophy here applicable in their fields as well.