This paper analyzes the most significant events occurring in Brazil's educational, social and political areas over the last half century, viewed against a background of relevant worldwide events. The hypothesis presented here is that the relations between the country's educational policies, the demands of the various segments of academia, and the public school system have always been strained. This strain has contributed positively to the evolution of academic knowledge and production, to the design of more modern curricular projects by institutional authorities, and to the initial recognition of the specific construction of school knowledge by the school system itself. However, the interaction of these major institutions lacks a crucial element--one that would lead to an effective change in the education of science teachers and produce a positive impact on Brazil's schools--namely, the wholehearted participation of science teachers themselves. With this analysis, we intend to contribute by offering some perspectives and proposals for science teacher education in Brazil.