Universal laws

The mechanist assumes that universal laws of nature govern all-natural events, including human development and behavior. This reductionist view asserts that understanding the parts of a system leads to understanding the entire system.

For example, understanding how atoms and molecules function helps the scientist understand chemistry and physics, which explain universal laws that apply to human chemistry, physiology, psychology, and sociology. However, mechanists do not necessarily claim to explain human development, but to "reduce the phenomena of physiological, psychological, and social functioning to the fundamental level of analysis—the laws of chemistry and physics" (Lerner, 2002, p. 51).

Therefore, with enough knowledge of chemistry and physics, there would be no need for the sciences of human development physiology, psychology, or sociology (Lerner, 2002). For example, Hunt and Ellis (2004) state that cognitive psychologists can be "thoroughly mechanistic" (p. 12), choosing the computer model to explain how the brain processes information.

When looking through the mechanistic lens, cognitive psychologists attempt to explain mental processes by discovering their origins in the brain. In other words, knowing the parts and understanding how those parts work together will help explain the workings of the machine.