Regulatory science underpins scientific regulations, including reflection papers, guidelines, and administrative notices, and is closely related to the quality assurance (QA) of pharmaceuticals, foods, and chemicals in our living environment. Historically, QA has been considered the basis of pharmaceutical science. Therefore, the Pharmaceutical and Medical Device Law specifies that pharmacists, as marketing directors of pharmaceutical products, are responsible for their QA. Furthermore, a pharmacist is responsible for the QA of foods and environmental chemicals by several laws; for example, as a food sanitation supervisor or an environmental sanitation training officer. This suggests that the professional expertise of pharmacists is expected in medical care where pharmaceuticals are used and in other fields associated with QA. Thus, I consider that the professionalism of a pharmacist is guided by spiritual concepts with a pragmatic attitude and conformance to these expectations.