Jacques Derrida was a 20th century French philosopher known for developing the concept of deconstruction. Deconstruction examines the assumptions and contradictions within texts. Derrida argued that meanings are not fixed and that there are many possible interpretations of a text. He also believed that a text contains absences and what is not said is as important as what is said. Derrida developed new concepts like "différance" and challenged the traditional privileging of speech over writing and presence over absence in philosophy.