The biological objection against strong AI

According to the biological objection against strong artificial intelligence (AI), machines cannot have human mindedness - that is, they cannot be conscious, intelligent, sentient, etc. in the precise way that a human being typically is - because this requires being alive, and machines are not alive. Proponents of the objection include John Lucas, Hubert Dreyfus, and John Searle. The present paper explains the nature and significance of the biological objection, before arguing that it currently represents an essentially irrational position.