One approach to field theory in argumentation begins with a description of argumentation and, by identifying similarities or regularities in discursive practice, attempts to induce the nature and characteristics of a field. The controversy surrounding the use of Laetrile, a proposed cancer treatment, provides an example of this approach. Assuming that the articles on the subject represent a field of argument, one can look beyond individual issues, such as defining the nature of the Laetrile problem and determining if it is toxic, in order to arrive at some principle indicating how issues stand in relation to one another. This locates the unity of the field or argument, not in either the content or the disciplinary purposes of the arguers, but in the proposition of the question of whether the medical community should conduct a clinical trial of the drug. The proposition points to a set of issues that must be addressed in order to make a judgment on it. Thus it is the nature of the proposition that provides the most productive way to identify a field of argument. Such a view makes it possible to see the connections among all the elements of argumentation. It also recognizes the possibility that a given institution or professional group can address more than one kind of proposition, or alternatively, that a given subject matter may find similar treatment in more than one professional group. (HOD)