Scientific textbooks are often said to deliver a stereotyped kind of knowledge, which conceals rather than reveals the real making of science. They may, however, alternatively be regarded as of peculiar interest for historians of science. An over-mechanical application of the Kuhnian concepts of ‘scientific revolution’ and ‘normal science’ can lead to the neglect of the internal dynamics of ‘normal science’. Scientific textbooks may provide a better understanding of the process of normalization in science.