This chapter shows how crucial aspects of organizational knowledge and organizational inquiry can be exactified using a relatively small number of abstract concepts common to various areas of human endeavor, such as (exact) philosophy, business management, science, and technology. Abstraction and exactification are essential for taming complexity in general and complexity of the modern-day organization in particular. Exactification is achieved, first and foremost, by creating and using ontologies—business and organizational domain models with precisely defined semantics. An ontology clearly demonstrates the fundamental concepts of a domain and relationships between them. The semantics of generic concepts used in effective modeling is based on mathematics and philosophy, while in too many cases a multitude of concepts invented in buzzword-compliant IT methods has no clear semantics and therefore cannot be reasonably used. Organizational learning and organizational inquiry can be understood and accomplished substantially better in the well-defined contexts of the domain ontologies that provide a foundation of organizational knowledge.