"Postmodernity" is the state or condition of being postmodern – after or in reaction to that which is modern, as in postmodern art ("see postmodernism"). Modernity is defined as a period or condition loosely identified with the Progressive Era, the Industrial Revolution, or the Enlightenment. In philosophy and critical theory "postmodernity" refers to the state or condition of society which is said to exist "after" modernity, a historical condition that marks the reasons for the end of modernity. This usage is ascribed to the philosophers Jean-François Lyotard and Jean Baudrillard.