Debates concerning philosophical grounds for the validity of classical and intuitionistic logics often have the very nature of proofs as a point of controversy. The intuitionist advocates for a strictly constructive notion of proof, while the classical logician advocates for a notion which allows the use of non-constructive principles such as reductio ad absurdum. In this paper we show how to coherently combine logical ecumenism and proof-theoretic semantics ( \(\boldsymbol{\mathrm{PtS}}\) ) by providing not only a medium in which classical and intuitionistic logics coexist, but also one in which their respective notions of proof coexist. Intuitionistic proofs receive the standard treatment of \(\boldsymbol{\mathrm{PtS}}\) , whereas classical proofs are given a semantics based on ideas by David Hilbert. Furthermore, we advance the state of the art in \(\boldsymbol{\mathrm{PtS}}\) by introducing a key contribution: treating the absurdity constant \(\bot\) as an atomic proposition and requiring all bases to be consistent. This treatment is essential for the obtainment of some ecumenical results, and it can also be used in standard intuitionistic \(\boldsymbol{\mathrm{PtS}}\) . Additionally, we employ normalization techniques to demonstrate the consistency of simulation bases. These innovations provide fresh technical and conceptual insights into the study of bases in \(\boldsymbol{\mathrm{PtS}}\) .
