“A classic example demonstrating necessary causation tells the story of a
fire that broke out after someone struck a match, and the question is “What
caused the fire, striking the match or the presence of oxygen in the room?”
Note that both factors are equally necessary, since the fire would not have
occurred absent one of them. So, from a purely logical point of view, the two
factors are equally responsible for the fire. Why, then, do we consider lighting
the match a more reasonable explanation of the fire than the presence of
oxygen?”