Preamble The emergence of machine intelligence during the second half of the twentieth century is the most important development in the evolution of this planet since the origin of life two to three thousand million years ago. The emergence of machine intelligence within the matrix of human society is analogous to the emergence, three billion years ago, of complex, self-replicating molecules within the matrix of an energy-rich molecular soup - the first step in the evolution of life. The emergence of machine intelligence within a human social context has set into motion irreversible processes which will lead to an evolutionary discontinuity. Just as the emergence of "Life" represented a qualitatively different form of organisation of matter and energy, so will pure "Intelligence" represent a qualitatively different form of organisation of matter, energy and life. The emergence of machine intelligence presages the progression of the human species as we know it, into a form which, at present, we would not recognise as "human". As Forsyth and Naylor (1985) have pointed out: "Humanity has opened two Pandora's boxes at the same time, one labelled genetic engineering, the other labelled knowledge engineering. What we have let out is not entirely clear, but it is reasonable to hazard a guess that it contains the seeds of our successors".