  The significance of this conception of reaching understanding and of rationally motivated agreement can also be seen by contrasting this account with other conceptions of understanding and interpretation, such as Gadamer's hermeneutics. Given Habermas's conception of speech acts and their relation to validity claims, it is not surprising that he argues that “communicative actions always require interpretations that are rational in approach” (TCA 1: 106), that is, ones that are made in the performative attitude by an interpreter. In general, Habermas agrees with hermeneutics that the whole domain of the social sciences is accessible only through interpretation, precisely because processes of reaching understanding already at work in the social sciences have antecedently constituted them (ibid., 107). But he draws a distinctive conclusion. Although social scientists are not actors, they must employ their own pretheoretical knowledge to gain interpretive access through communicative experience. As a “virtual participant,” the social scientist must take a position on the claims made by those he observes: he has access through communicative experience only “under the presupposition that he judges the agreement and disagreement, the validity claims and potential reasons with which he is confronted” (ibid., 116). There is then no disjunction between the attitude of the critic and the interpreter as reflective participants. Social scientists may withhold judgments, but only at the cost of impoverishing their interpretation and putting out of play their pretheoretical, practical knowledge that they have in common with others who are able to reach understanding. Thus, various forms of rationality become essential to the social sciences, because of the nature of the social domain. 