  In the 1980s John Searle argued in Intentionality (1983) (and further in The Rediscovery of the Mind (1991)) that intentionality and consciousness are essential properties of mental states. For Searle, our brains produce mental states with properties of consciousness and intentionality, and this is all part of our biology, yet consciousness and intentionality require a “first-person” ontology. Searle also argued that computers simulate but do not have mental states characterized by intentionality. As Searle argued, a computer system has a syntax (processing symbols of certain shapes) but has no semantics (the symbols lack meaning: we interpret the symbols). In this way Searle rejected both materialism and functionalism, while insisting that mind is a biological property of organisms like us: our brains “secrete” consciousness.