Property is theft! (French: La propriété, c'est le vol!) is a slogan coined by French anarchist Pierre-Joseph Proudhon in his 1840 book What is Property? Or, an Inquiry into the Principle of Right and of Government.
If I were asked to answer the following question: What is slavery? and I should answer in one word, It is murder!, my meaning would be understood at once. No extended argument would be required to show that the power to remove a man's mind, will, and personality, is the power of life and death, and that it makes a man a slave. It is murder. Why, then, to this other question: What is property? may I not likewise answer, It is robbery!, without the certainty of being misunderstood; the second proposition being no other than a transformation of the first?-- Pierre-Joseph Proudhon, What is Property?[I]
By "property", Proudhon referred to a concept regarding land property that originated in Roman law: the sovereign right of property, the right of the proprietor to do with his property as he pleases, "to use and abuse," so long as in the end he submits to state-sanctioned title, and he contrasts the supposed right of property with the rights (which he considered valid) of liberty, equality, and security. Proudhon was clear that his opposition to property did not extend to exclusive possession of labor-made wealth.
In the Confessions d'un revolutionnaire Proudhon further explained his use of this phrase:
In my first memorandum, in a frontal assault upon the established order, I said things like, Property is theft! The intention was to lodge a protest, to highlight, so to speak, the inanity of our institutions. At the time, that was my sole concern. Also, in the memorandum in which I demonstrated that startling proposition using simple arithmetic, I took care to speak out against any communist conclusion.
In the System of Economic Contradictions, having recalled and confirmed my initial formula, I added another quite contrary one rooted in considerations of quite another order--a formula that could neither destroy the first proposition nor be demolished by it: Property is freedom. ... In respect of property, as of all economic factors, harm and abuse cannot be dissevered from the good, any more than debit can from asset in double-entry book-keeping. The one necessarily spawns the other. To seek to do away with the abuses of property, is to destroy the thing itself; just as the striking of a debit from an account is tantamount to striking it from the credit record.
Jacques Pierre Brissot had previously written, in his Philosophical Inquiries on the Right of Property (Recherches philosophiques sur le droit de propriété et le vol), "Exclusive property is a robbery in nature." Marx would later write in an 1865 letter to a contemporary that Proudhon had taken the slogan from Warville, (that is, from Brissot) although this is contested by subsequent scholarship.
The phrase also appears in 1797 in the Marquis de Sade's text L'Histoire de Juliette: "Tracing the right of property back to its source, one infallibly arrives at usurpation. However, theft is only punished because it violates the right of property; but this right is itself nothing in origin but theft".
Similar phrases also appear in the works of Saint Ambrose, who taught that superfluum quod tenes tu furaris (the superfluous property which you hold you have stolen) and Basil of Caesarea (Ascetics, 34, 1-2).
Jean-Jacques Rousseau made the same general point when he wrote: "The first man who, having enclosed a piece of ground, bethought himself of saying 'This is mine', and found people simple enough to believe him, was the real founder of civil society. From how many crimes, wars, and murders, from how many horrors and misfortunes might not any one have saved mankind, by pulling up the stakes, or filling up the ditch, and crying to his fellows: Beware of listening to this impostor; you are undone if you once forget that the fruits of the earth belong to us all, and the earth itself to nobody."
Karl Marx, although initially favourable to Proudhon's work, later criticised, among other things, the expression "property is theft" as self-refuting and unnecessarily confusing, writing that "'theft' as a forcible violation of property presupposes the existence of property" and condemning Proudhon for entangling himself in "all sorts of fantasies, obscure even to himself, about true bourgeois property".
Max Stirner was highly critical of Proudhon, and in his work, The Ego and Its Own, made the same criticism of Proudhon's expression before Marx, asking, "Is the concept 'theft' at all possible unless one allows validity to the concept 'property'? How can one steal if property is not already extant? ... Accordingly property is not theft, but a theft becomes possible only through property."