Alois Riehl'

Critical Realism 

Spatial and Temporal Foundations 

of Science

Pierre Soulages: Le Noir 2015 (Detail)

The Project


Alois Riehl develops a sophisticated philosophy of realism in his three-volume work Der philosophische Kritizismus (aka The Principles of the Critical Philosophy, 1876, 1879, 1887), defending it in line with his dictum "Sentio, ergo sum et est." Although the issue of mind-independent reality has been widely and vigorously discussed in the history and philosophy of science, Riehl’s book has largely been forgotten.

This project presents a historical contextualization of Riehl’s realist-inspired views about science, alongside neo-Kantianism and Positivism. In doing so, it highlights the theory of time and space for the first time in a comprehensive way and is a key to understanding critical realism and making it accessible to current debates on realism/antirealism.

By focusing on Riehl’s revision of Kant’s doctrine of space and time, and its adaptation for the positive sciences, it becomes possible to understand The Principles of the Critical Philosophy as a problem-oriented system that brings together all partial aspects and provides a comprehensive systematic investigation (research cluster 1). 

In order to provide a historical analysis of Riehl’s theory of space and time (especially from the 1860s to the 1880s), the project examines the Principles of the Critical Philosophy on the basis of concrete scientific problems, such as the status of geometric axioms, the dimension of the world, the cause-effect relationship, and the determination of the limits of physiology and psychology (research cluster 2).

This results in a conception of philosophy of science in which the seemingly anachronistic adherence to the apriority of space and time enables a principles-based empiricism and thus a critical but qualitative realism (research cluster 3).

These three theoretical research clusters, as well as an evaluation of all the relevant source materials provide the starting point for a critical (not historical-critical) new edition of The Principles of the Critical Philosophy published by the Meiner Verlag (research cluster 4).

Two methods are combined within the project: The first is a contextualizing approach that delivers a fundamental philosophical investigation of Riehl’s theory of space and time; and the second is a philological approach that delivers a new edition of the Principles of the Critical Philosophy.

This project makes a very important book accessible once again — both to experts and to a wider readership — with the new edition, an international conference, and various papers.

Portrait Alois Riehl, Sammlung Ismael Gentz.

Funded by

German Research Foundation

 Project number: 521640504

Based at

Ruhr University of Bochum

Chair of Philosophy and History of Science