In Psychoanalysis, its image and its public Moscovici introduced the theory of social representations and took further the project of rehabilitating common sense. In this paper I examine this project through a consideration of the problem of cognitive polyphasia, and the continuity and discontinuity between different systems of knowing. Focusing on the relations between science and common sense. I ask why, despite considerable evidence to the contrary, the scientific imagination tends to deny its relation to common sense and believe that (...) can displace it. I argue that the psychosocial dynamic between common sense and science is revealing of how heavily they are entangled in, and indeed indebted to each other. Even more, this dynamic allows for a full appreciation of what the theory of social representations calls states of cognitive polyphasia. Different systems of thinking and knowing do not displace each other but live side by side, co-existing in a variety of ways, fulfilling different functions and answering different needs in social life. (shrink)