Deleuze is a key figure in postmodern French philosophy. Considering himself an empiricist and a vitalist, his body of work, which rests upon concepts such as multiplicity, constructivism, difference, and desire, stands at a substantial remove from the main traditions of 20th century Continental thought. His thought locates him as an influential figure in present-day considerations of society, creativity and subjectivity. Notably, within his metaphysics he favored a Spinozian concept of a plane of immanence with everything a mode of one substance, and thus on the same level of existence. He argued, then, that there is no good and evil, but rather only relationships which are beneficial or harmful to the particular individuals. This ethics influences his approach to society and politics, especially as he was so politically active in struggles for rights and freedoms. Later in his career he wrote some of the more infamous texts of the period, in particular, Anti-Oedipusand A Thousand Plateaus. These texts are collaborative works with the radical psychoanalyst Félix Guattari, and they exhibit Deleuze’s social and political commitment.