Although the words reasoning or being able to reason appear 480 times in today's curriculum Lgr 11, there are no explanations and justifications why students should learn and be assessed based on the knowledge requirements in their ability to reason. This paper examines how this can be found, mainly in the syllabus in civics education for grades 4-6, and whether the relevance of reasoning has been similar in previous curricula from 1962 to the present day. With quantitative content analysis and qualitative text analysis, curricula in social studies and commentary material have been analysed.    The analyses have been made based on the curriculum philosophies progressivism, essentialism and reconstructivism, as a theoretical framework and a possible way to explain the quantitative and qualitative results, and answer the purpose of the essay how the relevance has changed. Another purpose of the essay is to investigate how the change has been justified and whether a change in perception of knowledge can explain the varied occurrence of the ability to reason, or how important one have considered the ability to be. The results of the essay shows that the quantitative results are not entirely related to the qualitative ones. Although the words occur most times in Lgr 11, I find that the greatest relevance to reasoning is given in Lgr 80. One possible reason for this may be that Lgr 80 expresses a reconstructive view of knowledge where the learning process is in focus, rather than an essentialist view of knowledge as in Lgr 11, where the subject content is the most central.