Butler argues that identity is not something that is fixed and inherent, but rather something that is performed and enacted through discourse and social interactions.

Butler uses the term "performativity" to describe the way in which language and discourse shape and construct reality, and how they can be used to create and maintain certain identities and power structures.

Butler argues that power operates through the production and circulation of knowledge, and that certain forms of knowledge can be used to legitimize and maintain certain forms of power.

Butler argues that identity and power are mutually constitutive, meaning that they shape and influence each other. Identity is not simply a reflection of power, nor is power simply a tool for enforcing identity. Rather, they are two sides of the same coin.

Butler's theory of performativity challenges traditional notions of identity by arguing that identity is not fixed and immutable, but rather fluid and constantly changing. This is because identity is performative and enacted through discourse, and discourse is constantly changing and evolving.

Butler's theory of performativity suggests that social and political change is possible through discursive and performative practices, such as challenging and subverting dominant discourses and creating new and alternative forms of discourse.

Essence is not a key concept in Butler's theory of performativity. Butler argues that identity is not fixed and immutable, but rather fluid and constantly changing. This is because identity is performative and enacted through discourse, and discourse is constantly changing and evolving.

Butler's theory of performativity has been influential in a wide range of academic disciplines, including gender studies, cultural studies, and political science. However, it has not been as influential in mathematics.

Butler's theory of performativity has been criticized for being too abstract and theoretical, for being too focused on identity and neglecting other aspects of social life, and for being too pessimistic and not offering any hope for social change. However, it has not been criticized for being too optimistic and ignoring the realities of power and oppression.

Michel Foucault, Jacques Derrida, and Judith Butler are all scholars who have been associated with Butler's theory of performativity. John Searle is not associated with Butler's work.