Adorno's philosophy of the nonidentical grows out of the tension at the heart of rational thought: between the subject's need to identify and conceptualize, and the object's own objectivity, the nonidentical that is erased in a thought cut to fit. Our conceptual framework makes us all "identity thinkers"—we identify every object we perceive as an instance of something, thereby eliminating what makes that object unique. This brief chapter introduces Adorno's claim that the implications of this epistemological shortcoming are far-reaching, and very concrete. For him, social structures of domination, the withering of individual experience, social ills such as bigotry, racism, authoritarianism, political polarization, and ultimately even genocide, all hark back to identity thinking and the nonidentical, and with it to the most fundamental underpinnings of constitutive subjectivity.