Abstract: This essay is a personal reflection on John Long’s keynote address at the BCS People and Computers meeting in Nottingham in the summer of 1989. I try to locate the paper’s purpose and significance within the history of human-computer interaction (HCI), both prior to 1989 and subsequently, and particularly with respect to the abiding questions of what sort of enterprise HCI is, and of what sorts of knowledge it uses and produces. [Copyright &y& Elsevier]