The House of Lords' decision in Miller v Miller, McFarlane v McFarlane is to be welcomed for the guidance it gives about matters such as conduct in ancillary relief cases. This commentary argues that crucial issues of principle were left unresolved in the House's earlier decision in White v White, and that what was most needed from Miller/McFarlane was a decisive theoretical lead from the House of Lords which would enable us to predict the operation of the yardstick of equality in the face of new issues. Unfortunately the fact that there were conflicting opinions given, and that the theoretical difficulties were not fully addressed or resolved, leaves the operation of section 25 of the Matrimonial Causes Act 1925 the subject of considerable uncertainty.