This volume contains papers by many well-known scholars, most of whom have been directly influenced by Alonzo Church’s work. Often the emphasis is on foundational issues in logic, mathematics, computation, and philosophy - as was the case with Church’s contributions, now universally recognized as having been of fundamental significance in those areas. The volume should prove of interest to logicians, computer scientists, philosophers, and linguists. The contributions concern classical first-order logic, higher-order logic, non-classical theories of implication, set theories with universal sets, the logical and semantical paradoxes, the lambda-calculus, especially as it is used in computation, philosophical issues about meaning and ontology in the abstract sciences and in natural language, and much else.