Could a machine be conscious?

This question is much more diffi cult than the already diffi cult question posed by Turing. When we ask, ‘Can a machine think?’, there are two obvious paths to take. First, we may say that it depends what is meant by ‘think’, with the implication that this is somewhat arbitrary and that there are different answers according to different, equally valid, defi nitions. Second, we may do as Turing did and cut through the arguments by setting an objective test for thinking.