The Frankfurt School is a school of thought in sociology that traces its origins to Marxist thought. The Frankfurt School's ideas are also known as critical theory.
The major tenet of this school is that knowledge about what is best for society comes not from experience but from reason or logic. Because all people have the capacity to reason, all should be able to participate in creating society and the rules that govern it. Starting from this idea, scholars of this school of thought can analyze and critique socieites. Their basis for critique is that all societies should allow all groups to participate fully in political and economic life. Any society that does not allow this or which deprives some groups of power is not a good and rational society.