This paper presents a rationale for using a biographical approach in understanding how teachers think and act and how they have come to think and act in the way they do. This approach is seen as being able to provide a fundamental understanding of the teacher's perspective. Understanding how teachers individually and collectively think, act, develop professionally, and change during their careers might provide new insights as to how one might approach necessary reform, change, and improvements in education. The main part of the paper attempts to illuminate the potential of this approach through descriptions of two teachers' autobiographies. An effort at collaborative interpretation of these biographies is provided to identify the nature, sources, and manner of evolution of the special kind of thinking, action, and knowledge that pertains to their teaching. A brief comparative analysis is included to reveal similarities and differences and illustrate themes that might characterize the personal practical knowledge of other teachers. (JD)