This study aims at presenting a grid for analysing the way the language employed in Greek school science textbooks tends to project pedagogic messages. These messages are analysed for the different school science subjects (i.e., Physics, Chemistry, Biology) and educational levels (i.e., primary and lower secondary level). The analysis is made using the dimensions of content specialisation (classification) and social-pedagogic relationships (framing) promoted by the language of the school science textbooks as well as the elaboration and abstraction of the corresponding linguistic code (formality), thus combining pedagogical and socio-linguistic perspectives. Classification and formality are used to identify the ways science textbooks tend to position students in relation to the interior of the corresponding specialised body of knowledge (i.e., in terms of content and code) while framing is used to identify the ways science textbooks tend to position students as learning subjects within the school science discourse. The results show that the kind of pedagogic messages projected by the textbooks depends mainly on the educational level and not particularly on the specific discipline. As the educational level rises a gradual move towards more specialised forms of scientific knowledge (mainly in terms of code) with a parallel increase in the students' autonomy in accessing the textbook material is noticed. The implications concern the way both students and teachers approach science textbooks as well as the roles they can undertake by internalising the textbooks' pedagogic messages and also the way science textbooks are authored.