Reflective practice is a frequently used but in-frequently defined concept in nursing at the present time. Part of the reason for the lack of definition lies in the fact that there is no theory of practice. This paper lays the foundations for a theory of practice and paves the way for one useful way in which the relationship between theory and practice can be understood. It is suggested that thoughtful practice is often mistaken for reflective practice, but that the latter can only exist where practice is not taken for granted and so the outcome of practice is more learning from experience. The paper also maintains that for reflective practice to be practised within the profession it is necessary both to have the structures within which it can be encouraged and the theoretical foundation whereby efficient practice need not only be judged in terms of 'value for money'.