North American naturopathic medicine in the 21st century: Time for a seventh guiding principle - Scientia Critica.

•The regulation of naturopathic medicine is expanding in North America.•The fundamental principles are, in theory, aligned with public health and preventive medicine.•Naturopathic medicine has evolved from origins which have not prioritized critical analysis.•It is proposed that naturopathic medicine include Scientia Critica – critical appraisal and critical consciousness – into its core principles.