but the distinctively linguistic expertise of the interactional expert appears to have been overlooked. In this context, it must be emphasised that interactional expertise is a tacit knowledge-laden ability and thus similar in kind to the more embodied contributory expertise. This means that, like contributory expertise, interactional expertise cannot be acquired from books alone and it cannot be encoded in computerised expert systems. It is a specialised natural language and, as such; it can only be acquired by linguistic interaction with experts. The difference between interactional and contributory expertise is that, in the case of interactional expertise, the tacit knowledge pertains to the language of the domain but not its practice. In the case of contributory expertise, tacit knowledge relating to both the language and practice must be acquired. Significance The concept of interactional expertise provides a new way of engaging with traditional problems in the philosophy of knowledge appears to be implicated in a wide range of social activities, ranging from some styles of management in large organisations to high level specialist journalism to the peer review that is at the centre of science. Interactional expertise and philosophy In standard philosophy of knowledge the key distinction is between knowledge that is embodied and knowledge that is formally and explicitly articulated. In this dichotomous formulation, knowledge exists either as codified rules and facts or as some intangible property of the body that performs the task. This distinction forms the basis of the key debate about artificial intelligence research in which Hubert Dreyfus, starting from Heidegger argued that because computers don’t have bodies they can’t do what humans do and will not, therefore, succeed in becoming intelligent, no matter how sophisticated and detailed the knowledge base and rules with which they are programmed (see Dreyfus 1972). In 1990, Harry Collins developed an alternative critique of AI which, although similar to Dreyfus’s in that it suggested fundamental limits to what AI could achieve, grounded this explanation in an understanding of socialisation rather than embodiment. Collins’s argument was that because computers are asocial objects that cannot be socialised into the life of a community, then they cannot be intelligent. In this sense, Collins is taking the alternative to the 'thinking machine' first proposed by Alan Turing in 1950 (and now known as the Turing test) in which so-called intelligence in a machine is defined as the ability to hold a conversation. In the