Commentary - Is the future of "population/public health" in Canada united or divided? Reflections from within the field.

INTRODUCTION: "Are population and public health truly a unified field, or is population health simply attaching itself to public health as a means of gaining credibility?" This commentary was prompted by the above question, which was asked during K. L.'s PhD candidacy exam. In response, K. L. cited recent developments in the field to support her conviction that population and public health (PPH) existed positively as a unified discipline. However, through conversations that ensued over the subsequent weeks and months, we concluded that this issue goes deeper than the existence of departments and organizations labelled "population and public health," and may benefit from debate and discussion, particularly for the incoming generation of PPH scholars. In this commentary, we argue that (1) the PPH label at times implies a coherence of ideas, values and priorities that may not be present; (2) it is important and timely to work towards a more unified PPH; and (3) both challenges to and opportunities for a more unified PPH exist, which we illustrate using the broad areas of research funding, the public health workforce and PPH ethics.