What is Property? is one of the most notorious and influential works of social criticism of the nineteenth century and certainly the best-known book by
Pierre-Joseph Proudhon,　revolutionary author and contemporary of Marx.　Proudhon’s short answer to this question “Property is theft” was even morenotorious,
linking private property as it did whth the worst features of “bourgeois” political hegemony and exploitation. Yet because of the eagerness of later admirers to place Proudhon in one later tradition or another (socialist, utopian, anarchist, fascist, etc.) the intellectual qualities of his book have never been
fully appreciated; nor has his critique of the institution of nineteenth-century political thought in general. This new translation, with a critical and historical introduction to these neglected aspects of Proudhon’s "diabolical work"(as he called it), tries to do justice to the work of this subversive critic who himself, through his assault on the central institution of modern Western society, spent his whole life in quest of social justice.

Introduction
Bibliographical note
Chronology
What is Property?
Preface
1　Method followed in this work. Idea of a revolution
2　Property considered as a natural right. Occupation and civil law as efficient causes of property
　1.Property as a natural right
　2.Occupation as the basis of property
　3.Civil law as the foundation and sanction of property
3　Labour as the efficient cause of the domain of property
　1.Land cannot be appropriated
　2.Universal consent does not justify property
　3.Prescuiption never gives title to property
　4.Labour.That labour by itself has no power to appropriate the things of nature
　5.That labour leads to equality of property
　6.That in society all wages are equal
　7.That the inequality of faculties is the necessary condition of equality of fortunes
　8.That, in terms of justice,labour destroys property
4　That property is impossible
Property is physically and mathematically impossible
　1.Property is impossible because it demands something from nothing
　2.Property is impossible because wherever it exists, production costs more than it is worth
　3.Property is impossible because with a given capital production is proportional to labour,not to property
　4.Property is impossible because it is homicide
　5.Property is impossible because with it society devours itself
Appendix to the fifth proposition
　6.Property is impossible because it is the mother of tyranny
　7.Property is impossible because in consuming what it receives it loses it ,because in saving it nullifies it ,and because in using it as capital it turns it against production
　8.Property is impossible because its power of ccumulation is infinite, while it is exercised only over finite quantities
　9.property is impossible because it is powerless against property
　10.Property is impossible because it is the negative of equality
5　Psychological exposition of the idea of the just and
the unjust and determination of the principle of government and right First part
　1.Of the moral sense in man and in animals
　2.Of the first and second degrees of sociability
　3.Of the third degree of sociability
Second part
　1.Of the causes of errors. The origin of property
　2.Characteristics of communism and of property
　3.Determination of the third social form. Conclusions
Notes
Index