What did vitalists believe about the forces that control living organisms?

Vitalists believed that living organisms are governed by a unique vital force that is distinct from the physical and chemical forces found in nonliving matter. They argued that this force is responsible for coordinating physiological actions, directing the development and form of an organism, and maintaining the harmonious behavior that characterizes living creatures.12

Because vitalists maintained that this force was not susceptible to experimental investigation, they often concluded that a truly experimental physiology was impossible. This perspective stood in direct opposition to the mechanistic view, which asserts that all biological processes can be explained by the same physical and chemical laws that govern the rest of the natural world. Over time, vitalism lost scientific prestige as more biological phenomena were successfully explained through physical and chemical analysis.21