In Giles Deleuze and Félix Guattari’s 1991 book What is Philosophy?, the writers make the argument that philosophers are things of their time, creators of concepts through which the world can be interpreted. Philosophy, juxtaposed alongside science and art, provides the fundamental constructs that those disciplines require as a kind of prima terra, before any art can be made, or any science can be done. Philosophers, then, are in the business of creating ontologies.

This is of course a rejection of truth, at least in the absolute sense of the word. Richard Rorty distinguished between the concepts that ‘the truth is out there’ versus ‘the world is out there’. This goes all the way back to Wittgenstein and language, and the relations between the subject and the world: truth can only exist with language; and language can only exist with a subject. Therefore truth can’t exist ‘out there’, only the world can be out there – with its phenomenona (Husserl) and forms (Plato) and things-in-themselves (Kant).