This article describes and discusses an epistemological approach to the education of science teachers that emphasizes similarities in knowledge and modes of acquiring it among children, scientists in their historical contexts, and student teachers. Advanced courses in science-teacher education aim to go beyond the attainment of scientific knowledge and pedagogical content knowledge toward the building of a guiding theory of action for teaching. This theory needs to be rooted in a broad understanding of what science is about, what is regarded as scientific knowledge, and how it is generated and evolves. These questions are of an epistemological nature. At the same time, theories of action for teaching science are also connected with questions on individual ways of learning and of acquiring meaning. Such questions are often answered by both cognitive and developmental psychologists. Even here epistemological consideration are essential. Constructivist epistemology, which describes the process of constructing knowledge both in individuals and among scientists, can serve as a basis for generating such a guiding pedagogical theory of teaching. Educating science teachers in the light of radical versions of constructivism can enhance this process. This article describes in detail a course entitled “The Growth of Thinking on Evolution,” which was taught to third-year student teachers and which illustrates the approach and discusses the rationale behind it.