Efficient cause

As to its efficient cause, wit owes its production to an extraordinary and peculiar temperament in the constitution of the possessor of it, in which is found a concurrence of regular and exalted ferments, and an affluence of animal spirits, refined and rectified to a great degree of purity.

There must be some efficient cause for each slight individual difference, as well as for more strongly marked variations which occasionally arise.

[H]e turned the corner where for years he had always paused; simply not to pause was an efficient cause for emotion.

In the production of a statue of Athena for the Parthenon, the bronze is the material cause; the shape and design of the statue is the formal cause; the sculptor is the efficient''' cause; the honor of the goddess (and the glory of Athens) is the final cause.