My dignity as a man, my human right which consists of refusing to obey any other man, and to determine my own acts in conformity with my convictions is reflected by the equally free conscience of all and confirmed by the consent of all humanity. My personal freedom, confirmed by the liberty of all, extends to infinity.
The materialistic conception of freedom is therefore a very positive, very complex thing, and above all, eminently social, because it can be realized only in society and by the strictest equality and solidarity among all men.

Man, Society, and Freedom (1871)