A main reason for using the history of science in classroom instruction is its utility in promoting students' understanding of the nature of science (NOS). As indicated in such documents as the "National Science Education Standards," it is important to help students develop their understanding of NOS so that they will become more critical consumers of the very scientific knowledge that increasingly impacts their daily lives. Using history of science in instruction is a potential contextual approach for students to explicitly and reflectively learn NOS tenets, and science education literature contains numerous examples of its use in this regard. This article provides a method for teachers who intend to use one or more episodes from the history of science to help their students explicitly and reflectively learn more informed NOS conceptions. An example of this approach is given using the work of Henry David Thoreau and introductory concepts of ecological forest succession. (Contains 1 table.)