Cronin , P – Lecturer in Nursing , Trinity College Dublin

ions that are composed of unchanging and essential elements or objects (Rodgers, 2000b). This view, subsequently, gained considerable sway through philosophers such as Descartes, Locke and Kant. Although their complex individual philosophies fundamentally differed, in that they disagreed as to whether concepts were innate or arose from experience, they all purported that they are mental entities that exist solely in the mind. Furthermore, rooted in their work is the implication that a relationship exists between concepts and objects. Subsequent philosophical discourse highlighted this relationship as problematic because of a perceived need to distinguish between a concept and its corresponding object. Frege (cited in Rodgers, 2000b) proposed that the relationship was one of a grammatical predicate. He viewed specific objects as proper names e.g. green, whilst concepts were predicated on the object e.g. ‘green is a colour’. Moreover, he argued specifically that a concept must be clearly defined and have a clear boundary. A concept should be expressed as a set of necessary and sufficient conditions that constitute its essence (characteristics/attributes) that do not change over time and enable it to be distinguished from all other concepts (Rodgers, 2000b). The ultimate goal is to be able to define