Where does action collide?

In mechanics, action is a single number assigned to a possible path of a system, obtained by adding up (integrating) a quantity called the Lagrangian over the time of the motion. Maupertuis stated the principle of least action in 1744, proposing that nature realises the path for which this accumulated quantity is smallest, and Hamilton's 1834 On a general method in dynamics recast mechanics around such a function and its differentiation. The referent is a mathematical quantity with dimensions of energy multiplied by time, computed over an entire trajectory, and it has nothing in common with a lawsuit, with conduct aimed at other people, or with an intended bodily movement.[1][2]

Unit

One number per candidate path, in units of energy times time (joule seconds)

Recovery means

Not applicable

Measured by

Computed as the time integral of the Lagrangian along a path, and extremised to yield the equations of motion

In sociology, social action is human conduct to which the acting person attaches a subjective meaning and which is oriented toward the behaviour of other people. Weber set out this idea in Wirtschaft und Gesellschaft (1922) as the basic unit that an interpretive sociology tries to understand, and Parsons's 1937 The Structure of Social Action built a general theoretical framework on it. The referent is meaningful, other-directed conduct treated as the elementary building block of social life, and it differs from a computed physical quantity, from a court proceeding, and from the narrower philosophical question of what makes a movement intentional at all.[3][4]

Unit

One meaningful, other-oriented act by a person

Recovery means

Not applicable

Measured by

Interpreted by reconstructing the actor's subjective meaning, and classified into types such as instrumental, value-rational, affectual, and traditional

In philosophy, an action is a piece of behaviour that an agent does intentionally, as opposed to something that merely happens to the body. Anscombe's 1957 Intention founded the modern study of this question by asking what distinguishes an action from a bare bodily event, and Davidson's 1963 Actions, Reasons, and Causes argued that an event is an action when it is caused in the right way by the agent's reasons. The referent is intentional doing itself and the conditions under which behaviour counts as done for a reason, a metaphysical question distinct from a physical integral, from a lawsuit, and from sociology's meaningful conduct oriented to others.[5][6]

Unit

One intentional act by an agent, done for a reason

Recovery means

Not applicable

Measured by

Analysed conceptually by the presence of intention and reasons, and probed through cases that separate action from mere happening