Luhmann further explains that if sociology wants to see itself as a ‘critical’ science it cannot simply interpret itself as an opposition science that takes sides in the dispute between progressive and conservative ideologies. This can only lead to a failure to reflect upon the unity of the difference. A ‘critical’ project would mean that sociology is in a position to distinguish and is able to reflect upon the use of its distinctions. … He identifies what he sees as ‘the disadvantages’ that can arise from importing into sociology ‘terms and concepts from daily usage concerning the traditional world of ethical ideas’. These disadvantages predominate where this ‘introduction of the moral into sociological concepts’ takes the form of a ‘critical demolition and surprising presentation of the familiar in unfamiliar ways or of unmasking ideological beliefs’. Clearly this is a mild but direct attack on members of the Frankfurt School who were indeed engaged in producing a version of sociology which involved investigations of what Luhmann regarded as moral issues and, in many instances, a commitment to one particular side in the moral debate. In the aftermath of the overthrow of National Socialism in the Second World War, this, for Luhmann, was indeed ‘an easy trick to perform’. Luhmann ends his Preface by telling his readers of a new kind of sociology, one that does not rely on moral implants but instead seeks ‘to establish its intellectual position in positive terms by formulating a theory of its own’.

XREF: Connects to systems theory reference to the 'unity of the difference' — evokes Luhmann's broader second-order observation framework.

Niklas Luhmann, Trust and Power, loc. 16