Efficient causation is Aristotle’s moving cause: the agent, event, or force that brings something about. Why did the vase break? Because I dropped it - a past event pushing a present effect into being. The sculptor’s chisel-strokes are the efficient cause of the statue, the parents of the child, the collision of the motion. Of the four causes it is the most familiar to modern ears, because it is the one modernity kept: cause as mechanism, explanation as tracing the chain of pushes backward through time.
For Aristotle, efficient causation was one thread in a four-fold weave - inseparable from the Material Causation it works upon, the Formal Causation it transmits (the sculptor works from a form), and the Final Causation it serves. The scientific revolution cut the other threads. Galileo, Descartes, and their heirs restricted legitimate explanation to matter and mechanism, and the wager paid off spectacularly in prediction and control: if you know the prior states and the forces, you can calculate what comes next and intervene. Efficient causation is the native causality of the machine, of system dynamics modelled as push-and-pull, of cybernetics and every simulation since.
The cost of the wager is the subject of the the meaning crisis critique: a world of only efficient causes is one where purpose is an illusion projected onto mindless matter, meaning is merely subjective, consciousness is a causally idle by-product, and free will is impossible - conclusions that follow not from evidence but from the initial narrowing of what counts as a cause. reductionism is efficient-materialist explanation universalized. Even the pioneers knew better: Newton’s private writings dwell far longer on formal and final questions than on the mechanics he is remembered for, suggesting the boundary was methodological, not metaphysical.
Understanding efficient causation means honouring its power while refusing its monopoly: it answers how something came about, brilliantly - and stays silent on what the thing is and what it is for.
See also Material Causation, Formal Causation, Final Causation, reductionism, system dynamics, cybernetics, ontology