Deconstruction is a critical outlook concerned with the relationship between text and meaning.  Jacques Derrida's 1967 work Of Grammatology introduced the majority of ideas influential within deconstruction. According to Derrida and taking inspiration from the work of Ferdinand de Saussure, language as a system of signs and words only have meaning because of the contrast between these signs. As Rorty contends "words have meaning only because of contrast-effects with other words...no word can acquire meaning in the way in which philosophers from Aristotle to Bertrand Russell have hoped it might—by being the unmediated expression of something non-linguistic (e.g., an emotion, a sense-datum, a physical object, an idea, a Platonic Form)". As a consequence meaning is never present, but rather is deferred to other signs. Derrida refers to the, in this view, mistaken belief that there is a self-sufficient, non-deferred meaning as metaphysics of presence. A concept then must be understood in the context of its opposite, such as being/nothingness, normal/abnormal, speech/writing, etc.