Stirner proposes that most commonly accepted social institutions – including the notion of State, property as a right, natural rights in general, and the very notion of society – were mere illusions, "spooks" or ghosts in the mind.[14]

He advocated egoism and a form of amoralism, in which individuals would unite in 'unions of egoists' only when it was in their self-interest to do so. For him, property simply comes about through might: "Whoever knows how to take, to defend, the thing, to him belongs property." And, "What I have in my power, that is my own. So long as I assert myself as holder, I am the proprietor of the thing." He says, "I do not step shyly back from your property, but look upon it always as my property, in which I respect nothing. Pray do the like with what you call my property!"[15] Stirner considers the world and everything in it, including other persons, available to one's taking or use without moral constraint[16] – that rights do not exist in regard to objects and people at all. He sees no rationality in taking the interests of others into account unless doing so furthers one's self-interest, which he believes is the only legitimate reason for acting. He denies society as being an actual entity, calling society a "spook" and that "the individuals are its reality" (The Ego and Its Own).

Stirner planned and financed (with Marie's inheritance) an attempt by some Young Hegelians to own and operate a milk-shop on co-operative principles. This enterprise failed partly because the dairy farmers were suspicious of these well-dressed intellectuals. The milk shop was also so well decorated that most of the potential customers felt too poorly dressed to buy their milk there.[citation needed]