An approach in achieving semantic interoperability among heterogeneous systems is to offer infrastructure to assist with linking and integration using a foundational ontology. Due to the creation of multiple foundational ontologies, this also means linking and integrating those ones. In order to achieve this, we have selected the widely used foundational ontologies DOLCE, BFO, and GFO, and their related modules, on which to perform ontology mediation (alignment, mapping, and merging). The foundational ontologies were aligned by identifying correspondences between ontology entities (...) using seven tools, documentation, and our manual alignments, and comparing their effectiveness. Thereafter, based on the alignments, we created correspondences in the ontology files resulting in entity mappings and merged ontologies. However, during the mapping process, it was found that differences in foundational ontologies, such as their hierarchical structure, conflicting axioms due to complement and disjointness, and incompatible domain and range restriction, cause logical inconsistencies in foundational ontology alignments, thereby greatly reducing the number of mappings. We analyse and present these logical inconsistencies with possible solutions to some of them. (shrink)