For almost three decades 'holistic health care' has been a widely invoked term. It is called upon as an antidote to mechanistic science, as justification for the use of alternative therapies, as instruction to good practice and even as a boundary marker in establishing professional identity. In the service of these intentions it has assumed various meanings. The first aim of this study is to identify from the literature, the illusion of shared meaning that saturates this term and to expose the implications of this lack of clarity. The elusive nature of the meanings attributed to holism and the problem of determining an appropriate method of pursuing these meanings is addressed. A particular understanding of conceptual analysis and practical reasoning are defended as adequate tools. The group of ideas from which the term holism can be distinguished, individualism, dualism and reductionism, form the context of the examination of understandings of wholeness. Eight distinctions of wholeness are examined and the common conceptual feature of 'purpose' is suggested. This requires considerable justification which is provided by an exploration of the notion of 'partness'. Recourse to the seminal work of Smuts (1926) is sought and the derivation of the idea of holism from evolution theory is explored. A key understanding explored is the nature of emergent properties and their role in the holistic doctrine, 'the whole is more than the sum of the parts'. Employment of the word holism in social science, philosophy, and biology is examined and a number of fallacies about holism exposed. With a somewhat clearer understanding of holism, and a working notion of wholeness, theories of health are discussed as contenders for a philosophical basis for 'holistic health care'. While several show some congruence, it is argued that the Foundations Theory of Health can be shown to demonstrate the characteristics of work for wholeness identified in this work. The conclusion that holistic health care is in essence working creatively with incipient wholes, is explained and justified by a discussion about how a health worker might become more holistic in her practice.