Something is said to be “in vain”, when the end for the sake of which it comes to be does not occur, e.g. if walking takes place for the loosening of the bowels; if this does not follow after that, we say that we have walked in vain and that the walking was vain, as “in vain” means this: something which is by nature for the sake of something else and fail to accomplish the end for the sake of which it was for.
So if this is what is in vain, the automatic, therefore, is well derived from that which is itself in vain. For we say that the stone automatically became such as to be for someone to sit on, as indeed the automatic is the cause for that; for “to be into the proper place” was the natural end of the stone’s moving downwards, yet another concurrent end has been followed to that, which is to become such as to sit on. Since, then, its moving downwards has become by virtue of concurrence the cause of such a shape, it is called automatic, as becoming itself in vain with regard to the concurrent happening.
The automatic outcome differs from what is in vain, as the final cause too differs from the efficient cause, in the same way as the outcome of luck differs from luck. In general, when the outcome is such as to have some proper efficient causes, yet without coming from pre-existent efficient causes, but from some others to which too another proper end comes on, then the pre-existent causes are said to have come to be in vain, since the presumable end has not come to be on account of them, whilst those which supervene automatically, in that they came to be without the presence of the proper origin in them before. For example, a stone that fell down and struck the man who was passing through. Here the strike stands as a purpose, and the fall, we would say, as an efficient cause. But also another proper origin was responsible for the strike, not the fall, but, for instance, to be thrown by someone for the purpose of striking someone else; and the fall came about not for the sake of the strike but for the sake of being carried into the proper place. And they became of each other by virtue of concurrence the one cause, the other end.
Bibliography: J. Philoponus in Aristotle’s Physics
Translation – text editing: George Kotsalis