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 famously argued that existence precedes essence, meaning that our existence as individuals comes before any predetermined or fixed nature or identity.

Edmund Husserl's phenomenology focuses on the study of consciousness, aiming to understand the structures and processes of our subjective experiences.

Martin Heidegger introduced the concept of 'Being-in-the-world', emphasizing the interconnectedness between human existence and the world we inhabit.

Jacques Derrida's post-structuralist philosophy emphasizes the role of language in shaping our understanding of reality, challenging traditional notions of truth and meaning.

Jacques Derrida is credited with coining the term 'deconstruction' in philosophy, a method of analyzing texts and discourses to reveal their underlying assumptions and power structures.

Friedrich Nietzsche's philosophy revolves around the concept of 'the will to power', arguing that the fundamental drive of all living beings is to seek power and dominance.

Friedrich Nietzsche introduced the concept of 'the Übermensch' (Superman), representing an ideal human being who transcends traditional moral and societal values.

Jean-Paul Sartre emphasized the importance of authenticity, arguing that individuals must embrace their own existence and take responsibility for their choices and actions.

Michel Foucault's post-structuralist theory includes the concept of 'the gaze', which examines how power structures and social norms shape our perceptions and understanding of the world.

Friedrich Schlegel, a key figure in early Romanticism, argued that truth is subjective and dependent on individual perspectives and interpretations.

Martin Heidegger introduced the concept of 'the hermeneutic circle', which emphasizes the interconnectedness between understanding a text and the context in which it was created.

Jacques Derrida's post-structuralist philosophy emphasizes the role of language as a system of differences, challenging traditional notions of meaning and stability.

Friedrich Nietzsche famously declared 'the death of God', symbolizing the decline of traditional religious beliefs and the rise of secular values in modern society.

Karl Marx's critique of capitalism emphasizes the concept of alienation, arguing that workers are alienated from their labor, the products of their labor, and from their own humanity.