Ludwig Wittgenstein, in his later work "Philosophical Investigations," placed the grammatical description of our everyday actions at the center of his considerations. This departure from essentialist-Aristotelian definitions of essence has lost none of its explosive power to this day. With Habermas, the "world-constituting performances" transitioned to "grammatical structures" in the 20th century. The subject's discourse about itself then appears in a new light: it is formulated in a grammatical way, with an awareness of the constant changeability of those rule systems that are translated into practice through grammatical standards. For the first time, this volume describes the category of grammatical subjectivity as an expansion of the reference framework within which people speak about themselves: with regard to themes such as knowledge, ethics, politics, and circumstances.