There are conditions that lead professors to use different text formats in quantum physics courses. Studying these conditions is an important aspect to understand the dynamics of physics pedagogy, and philosophy of science can be used as an orientation to do so. A case study was conducted at a Brazilian initial physics teacher training program. Using a framework based on Fleck's work, we investigate the thought style of the participating professor regarding reading and textual forms in physics education, as well as the relationship of this thought style with his choice of materials used in class--which may manifest resistances and points of entry for text formats in these contexts. The teaching practices of this professor in two physics courses, which had differing levels of comprehension regarding quantum physics, were analyzed through observations and a qualitative interview. The analysis of the professor's voice indicated an understanding of texts in disciplines of quantum physics influenced by cultural elements as described by Kuhn's philosophy on physics pedagogy. However, according to the style of thought that guides his perception of the students' training needs, entry to other texts (from other levels and digital materials) is promoted. These results can contribute to the development of theories on professors' choices and attitudes linked to the perception of training needs in undergraduate physics courses, as well as indicating that changes demand collective actions at the institutional level.