This article affirms the modern origin of sociology as a science and posits a critical posture as its fundamental component. As such, sociology is opposed to any dogmatic conception of knowledge. The critical stance has both internal and external dimension. Sociology is under the obligation to observe a constant vigilance towards the knowledge it produces. A considerable methodological privilege bestowed upon the researchers in sociology requires that they have to be capable of criticizing their conceptual tools and operational procedures. Furthermore, critical attitude consists also in questioning conditioning of results linked to the dependence arising from the subsidizing of research. These preconditions of critical posture are illustrated by consideration of the challenges of researching the so-called “school failure”. Ultimately, responsibility commands a sociologist to respect the principle of precaution. When political action is concerned, the researchers must demand that their rights of intellectual property be preserved. To criticize, in this sense, is not to denounce; nonetheless, sociology will only remain faithful to what can pass legitimately as its essence by demanding the right, against threats and seductions, to speak the truth about social reality. and Claude Javeau.