| Abstract: One distinctive characteristic of B.F. Skinner’s philosophical system is the acknowledgement of private events (e.g., thoughts, emotions, feelings, senses, etc.) as important parts of human behavior. At the same time, radical behaviorists oppose what they call mentalistic entities, such as mental representations, memory storages, and the mind. The status of private events is acknowledged and mentalistic entities are dismissed, in part because the former are viewed as observable phenomena (at least on a private level) while the latter as unobservable hypothetical constructs. However, recently, some philosophers have questioned the observable - unobservable distinction, considering it unfruitful, superficial, and flawed (e.g., Burgos & Killeen, 2019; Burgos, 2021). The present analysis attempts to formulate a coherent and productive system for distinguishing observable and unobservable entities, offering this way a potent argument against mentalism. The notion of observability is operationally defined in terms of the potential contact between an observer and a natural phenomenon, and its implications are examined. Specific criteria for asserting the observability of an entity are offered, with a special reference to the interpretation of currently unobserved phenomena. |