Stirner’s main work is Der Einzige und sein Eigenthum (in modern German spelling Der Einzige und sein Eigentum; engl. trans. The Ego and Its Own), which appeared in Leipzig in October 1844, with as year of publication mentioned 1845. In The Ego and Its Own, Stirner launches a radical anti-authoritarian and individualist critique of contemporary Prussian society, and modern western society as such. He offers an approach to human existence which depicts the self as a creative non-entity, beyond language and reality.
The book proclaims that all religions and ideologies rest on empty concepts. The same holds true for society’s institutions that claim authority over the individual, be it the state, legislation, the church, or the systems of education such as Universities.
Stirner’s argument explores and extends the limits of criticism, aiming his critique especially at those of his contemporaries, particularly Ludwig Feuerbach, and at popular ideologies, including religion, liberalism, and humanism (which he regarded as analogous to religion with the abstract Man or humanity as the supreme being), nationalism, statism, capitalism, socialism, and communism.
In the time of spirits thoughts grew till they overtopped my head, whose offspring they yet were; they hovered about me and convulsed me like fever-phantasies – an awful power. The thoughts had become corporeal on their own account, were ghosts, e. g. God, Emperor, Pope, Fatherland, etc. If I destroy their corporeity, then I take them back into mine, and say: “I alone am corporeal.” And now I take the world as what it is to me, as mine, as my property; I refer all to myself.— Max Stirner, The Ego and Its Own, p 15.
“Stirner went so far in his notorious work, Der Einzige und Sein Eigenthum (1845), as to reject all moral ideas. Everything that in any way, whether it be external force, belief, or mere idea, places itself above the individual and his caprice, Stirner rejects as a hateful limitation of himself. What a pity that to this book — the extremest that we know anywhere — a second positive part was not added. It would have been easier than in the case of Schelling’s philosophy; for out of the unlimited Ego I can again beget every kind of Idealism as my will and my idea. Stirner lays so much stress upon the will, in fact, that it appears as the root force of human nature. It may remind us of Schopenhauer. Thus there are two sides to everything.”
— History of Materialism, Second Book, First Section, Chapter II, “Philosophical Materialism since Kant”