I respond to Selinger and Mix (Selinger, E. and Mix, J. 2004. On interactional expertise: Pragmatic and ontological considerations. Phenomenology and the Cognitive Sciences 3: 145–163), concentrating on their charges that Collins (Collins, H. M. 2004a. Interactional expertise as a third form of knowledge. Phenomenology and the Cognitive Sciences 3: 125–143) underrates the importance of interactional expertise as an expertise sui generis and that the paper fails to analyse the idea of embodiment sufficiently holistically, misleading treating the "body' as no more than the linear sum of its parts.