Can you describe exactly what natural science is?

The term is often used interchangeably with physical science, which might be defined as scientific specialties that deal strictly with the physical world. A definition of natural science as associated with natural phenomena would seem to reference only physical events as well. However, some of the sciences that address natural phenomena do so by inventing a nonphysical universe in which events are said to exist and therefore be available to explain physical events. In fact, for such sciences, these nonphysical events are often of greater interest than the physical events they supposedly explain.The social sciences generally approach physical phenomena in this manner, psychology being the leading example. Most of the specialties in psychology practice a form of philosophical dualism in which behavior, a fully natural or physical phenomenon, is viewed as an epiphenomenon that is explained in terms of mental events. Mental events are not physical by definition and are said to exist in a mental world, about which there is no direct physical evidence. Any evidence about mental events collected in research projects is necessarily indirect, thereby raising difficult questions about the relationship between what is directly measured (behavior) and the validity of inferences between behavioral data and the mental events of actual interest. Aside from other problems, this approach violates the scientific strategy of parsimony. In sum, most people probably conflate natural and physical science, and with good reason. Most sciences targeting natural phenomena do address only physical events. However, a definition of natural sciences that includes all disciplines investigating life forms must confront important methodological distinctions between scientific disciplines that focus only on physical phenomena versus those that pursue putative nonphysical events as a primary subject matter.