On the Notion of Cause

“I put my penny in the slot, but before I can draw out my ticlket there is an earthquake which upsets the machine and my calculations. In order to be sure of the expected effect, we must know that there is nothing in the environment to interfere with it. But this mneans that the supposed cause is not, by itself, adequate to insure the effect. And as soon as we include the environiment, the probability of repetition is diminished, until at last, when the whole environment is included, the probability of repetition becomes almost niil.”

Betrand Russell