Purpose – The paper's purpose is to provide a commentary on “Case studies and differentiated realities” a paper by Sue Llewellyn published in Qualitative Research in Accounting & Management Vol. 4 No 1, 2007

Design/methodology/approach – The approach is to draw upon critical realist and other philosophy of social science to respond constructively to Llewellyn's paper.

Findings – Rejects the claim that we need a concept of plural realities rather than a concept of a single, differentiated reality. Endorses Llewellyn's argument that different meanings of objectivity and subjectivity often go unnoticed, undermining their user's arguments. Takes issue with Llewellyn's claim that surveys are better suited to stable situations and case studies for changing situations. Adds support to the defence of case studies against the charge of lack of representativeness, by drawing upon ontological arguments about part-whole relations and upon defences of practical reason.

Originality/value – The implication of these points is that a still stronger defence of case study approaches can be made.