The paper deals with the question whether it is possible or not to analyze sociology as a social system with its own instruments, that is, the instruments of sociological analysis. In other words, the paper deals with the question whether a sociology of sociology is possible (and desirable). The first obstacle for a radically reflexive sociology is a certain taboo of thematizing that is central for modern science (De nobis ipsis silemus). The received idea is that scientific research should be objective, independent from social contexts of science. For this purpose some techniques of objectivation have been developed, that is, the construction of authorship in order to avoid the thematization of the social context of a sociological text. In addition, there is a discrepancy between official and social criteria of sociological success. This discrepancy should not be thematized either. Thus, a sociological analysis of sociology is not possible. But even without the silemus rule, sociological research on sociology might be impossible.