K. I. Macdonald (this Journal, vi (1976), 380–2) asserts, first, that my claim that the concept of power is essentially contested is ‘technically mistaken’ and, second, that the mistake is ‘substantively pernicious’. Unfortunately, he does not succeed in showing what the mistake is – nor indeed what makes it ‘technical’, rather than just a mistake. He does not even try to show why this alleged mistake is pernicious – let alone substantively so.