Following a similar line of thought, Hume notices that the force that compels one event to follow another, causation, is also never experienced in sense impressions. All that is given in experience is the regular succession of one kind of event followed by another. But the supposition that the earlier event, the so-called ‘cause’, must be followed by the succeeding event, the ‘effect’, is merely human expectation projected onto reality. There is no justification for believing that there is any causal necessity in the ordering of events.
