Mécanisme

A mechanism, or mécanisme in French, is the process and structure by which a particular effect is produced. It involves the parts, their interactions, and the sequence of events that together yield a function. The term is used across science, engineering, and social sciences to explain how things work.

In engineering and physics, a mechanism is a system of rigid bodies arranged to transform input motion or force into a desired output. Classic simple machines such as levers, inclined planes, wedges, screws, pulleys, and wheels-and-axles are elementary mechanisms; more complex forms include gear trains, linkages, cams, and followers.

In biology, mechanisms explain how processes occur, including enzymatic catalysis, metabolic pathways, signal transduction, and genetic regulation. The pharmacological term mechanism of action describes how a drug produces its effect at cellular or molecular levels.

In the social sciences, mechanisms describe the processes by which actions by individuals or institutions lead to outcomes, such as incentive structures, information diffusion, and governance rules. Mechanism-based explanations emphasize causal steps and interactions rather than single laws.

Studying mechanisms often uses diagrams, causal graphs, and models to illustrate sequences of interaction and to test whether proposed steps reproduce observed phenomena. The goal is explanatory clarity, predictive power, and a basis for design and intervention.