Paul Lorenzen (1915–1994) was an outstanding philosopher from the latter half of the 20th century. His name is associated with the Erlangen School of Methodical Constructivism, of which the approach in linguistic philosophy and philosophy of science determined philosophical discussions especially in Germany in the 1960s and 1970s.

At that time, Lorenzen already had an international reputation as a brilliant mind in mathematics and logic. Focussing at first on abstract algebra, Lorenzen later turned his attention to foundational issues in logic and mathematics. His studies in this field are still highly regarded today and finally led to his concept of operative logic and mathematics, which in turn were the base for his philosophy later on.

This meeting focusses on integrating Lorenzen’s original approach into the history of logic and mathematics. We furthermore explore the options of how Lorenzen’s systematical ideas can be implemented in today’s debates on proof-theoretic semantics, databank management and stochastics.