Søren Kierkegaard is widely regarded as the father of Existentialism, a philosophical movement that emphasizes the importance of individual existence, freedom, and choice.

Jean-Paul Sartre argued that the fundamental human condition is anxiety, which arises from the realization of our freedom and responsibility in an indifferent universe.

Martin Heidegger's philosophy revolves around the concept of Being, which he explores through his analysis of Dasein, or human existence.

Hans-Georg Gadamer introduced the concept of the 'hermeneutic circle,' which refers to the dynamic relationship between the interpreter and the text, where each informs and shapes the understanding of the other.

Jacques Derrida's deconstruction primarily targets logocentrism, the privileging of speech and reason over writing and difference in Western thought.

Jean-François Lyotard is credited with coining the term 'post-structuralism' to describe the philosophical movement that emerged in the 1960s and 1970s, challenging the foundational assumptions of structuralism.

Michel Foucault's theory of power revolves around the concept of discourse, which he sees as a system of knowledge and practices that shape and regulate social relations.

Gilles Deleuze introduced the concept of the 'rhizome' to describe a non-hierarchical, interconnected network that challenges traditional notions of structure and organization.

Jürgen Habermas's theory of communicative action emphasizes the importance of intersubjectivity, or the ability to reach mutual understanding through rational discourse.

Gilles Deleuze's concept of 'nomadism' refers to a state of constant movement and becoming, challenging traditional notions of identity and rootedness.

Paul Ricoeur's hermeneutics focuses on the role of narrative in understanding human experience and meaning-making.

Jacques Derrida's concept of 'différance' refers to the inherent deferral and displacement of meaning in language and thought.

Emmanuel Levinas's philosophy centers around ethics, particularly the ethical relationship between self and other.

Michel Foucault's concept of 'the gaze' refers to the power dynamics and surveillance mechanisms that shape social relations.

Slavoj Žižek's philosophy draws heavily on psychoanalysis, particularly the work of Jacques Lacan, to explore social and political phenomena.