An example of an immediate cause is the extraction of water from the depths of the earth by means of a wheel with attached buckets, in which water is drawn out of the well. The remote cause is the man who harnesses a beast to the wheel and so makes the wheel revolve, which draws the water from the bottom of the well to the surface. The intermediate means between the man and the buckets are the beast, the pulley that moves each other, and the rope. If anything should go wrong with one of these means, the objective for which they are employed will not be reached. So it is with the other acts that are bought into actuality. They cannot arise from man or anything else, except by the decree of GD and unless He prepares the means for their completion. If the means are entirely lacking, none of the natural activities can be brought into actuality. pg 383