Hans Albert, in our slightly partisan view the most eminent twentieth century German philosopher of economics, celebrated his centennial in February 2021. In his honor, we have put together this special issue, Albert@100—a brief volume of essays meant to take stock of aspects of Albert’s work that are of particular interest for the readers of this journal and, more generally, for a PPE audience.

Among the wide-ranging interests of Hans Albert, economics holds a special place. Like Adam Smith, he conceived of economics as a general social science. He criticized neoclassical economics for its problematic methodology and its institutional, motivational and cognitive deficits. However, he thought that these deficits could be overcome, and that economics might develop approximate explanations of social phenomena and provide theoretical comparisons of alternative institutional arrangements as a basis for scientifically informed policies.

In this vein, Albert welcomed the development of public choice theory, of the law-and-economics movement, and of institutional economics in general. Early on, he urged economists to take cognitive social psychology and the experimental method seriously. Science, he argued, progresses through criticism, and building bridges between different fields opens up new possibilities of criticism. The aspiration of many economists to keep economics “pure”, by separating it from psychology and the other social sciences, he considered as an “immunization strategy”, a way of warding off criticism, and, therefore, as a recipe for stagnation.

After discovering the works of Karl Popper in the 1950s, Albert consistently pursued a critical-rationalist vision of a unified social science—extending from psychology over sociology and economics to legal theory, and from foundational micro-behavioral issues to issues of constitutional politics and the social order.

According to his vision, social theories need, and deserve, the same empirical scrutiny as theories in the natural sciences. With Max Weber, he defended the ideal of a value free social science: scientific advice, in the natural as well as the social sciences, is “technological”, that is, concerned with the questions of whether and, if so, how “given aims” can be reached. Against Max Weber, however, he argued that a rational (that is, critical) discussion of aims, ends and values is possible—though, of course, neither an ultimate nor a scientific justification. In this spirit, he criticized the idea of using the Pareto criterion as an allegedly “weak” value judgment for defining the scope and limits of normative economics. Rejecting welfare economic claims of providing a scientifically justified ranking of policy alternatives, he insisted that economists can and should use a plurality of values for evaluating these alternatives; the choice of the alternative to be implemented, however, should be a matter of political compromise in an open society.

In the 1960s, Albert defended the critical rationalist stance in the so-called “Positivismusstreit” (positivism controversy) in German social theory. This controversy reached an audience well beyond academia. At least in our personal view, the controversy suffered from the ideological spirit upheld by Adorno, Habermas, and most of the adherents of the Frankfurt School of Social Theory. We therefore thought that it should not be a focus of this special issue.

Still, the paper by Jitka Paitlova, which gives an overview of Hans Albert’s works, mentions this controversy among other controversies in which he was embroiled. Armin Engländer focuses on Hans Albert’s meta-ethical position. Both papers bear on the positivism controversy and Albert’s life-long efforts to uphold critical-rationalist standards in the area where (social) theory meets normative ethics and theology.

Max Albert’s paper is concerned with the methodology of economics and the kind of “model platonism” still lingering in modern economics. The paper of Geoffrey Brennan and Hartmut Kliemt addresses the status of the value-laden aim of adopting a critical rationalist stance of value-neutrality in economic philosophy. The same applies in case of Viktor Vanberg, who as a critical rationalist and eminent scholar of Buchanan and Hayek tries to push the envelope of value-neutral arguments in normative justifications of constitutional democracy as practiced in WEIRD (western, educated, industrialized, rich, and democratic) societies.

Hans Albert has always been, as the title of his autobiographical essay states, “embroiled in controversies.” It is not surprising, then, that the essays in this collection are often themselves contributions to controversies. But if asked, all contributors to this Special Issue would be subscribers to the values of an open society, including the open society of scholars of social theory, that Hans Albert has envisioned throughout his prolific and long academic career.