Methodological triangulation is the use of more than one method to investigate a phenomenon. Nurse researchers investigate health phenomena using methods drawn from the natural and social sciences. The methodological debate concerns the possibility of confirming a single theory with different kinds of met hods. The nursing debate parallels the philosophical debate about how the natural and social sciences are related. This article critiques the presuppositions of the nursing debate and suggests alternatives. The consequence is a view of triangulation that permits different methods to confirm a single theory. The article then explores the consequences for the philosophy of social science.