Box R contains a randomizing device; once activated it proceeds, in a perfectly random manner, to one of its one hundred different terminal states. Each of the terminal states may be supposed to be equally probable so that the probability of the box ending in state number 17 is .01. One can think of the device as embodying certain quantum mechanical processes—e.g. the emission of an electron … toward a screen which has one hundred different areas suitably marked off as terminal sights. Attached to Box R is a loaded revolver which fires when (and only when) the terminal state happens to be number 17. We take this device and place it next to a cat, point the revolver at the cat and activate the box. Things go badly for the cat; the improbable occurs and the cat is killed. The cat's master, if informed of our doings, would almost certainly insist that we had killed his cat… Though we designate our actions as the cause, and the cat's death as the result, there is no regular or uniform connection between actions of the first sort and results of the latter sort … We seem to have a situation which we are inclined to describe in a way which implies the presence of a causal connection between C and E and, yet, a situation in which it is clear that in identical circumstances something of type C will not even generally be followed by something of type E. ([1], pp. 69–70)