In 1978 and 1979, while a visiting fellow at Cambridge University, Orlando Patterson engaged in a number of conversations about slavery with Cambridge ancient historian M. I. Finley. Both men were at the time writing influential books on slavery that would mark important benchmarks in their careers and defined two approaches to the study of slavery, one fading in significance, the other introducing a comparative approach to the institution more focused on dynamics of power and social alienation. At the end (...) of 1978, Finley delivered at the Collège de France four lectures that summarized his thinking on the topic over more than thirty years; two years later they appeared in print under the title Ancient Slavery and Modern Ideology. In 1982 Patterson published Slavery and Social Death, a ground-breaking study that to this day remains unparalleled in its attempt to establish a globally valid definition of slavery applicable to some sixty-six slave-owning societies across three millennia. This article explores the intersection of these two works, the intellectual currents of the times in which they were produced, and the influence each exerted on the study of slavery in subsequent decades, as models and paradigms of two approaches to understanding the significance of the institution. (shrink)