In our search for the ultimate law, P, that allows us to encode the whole of reality we have come across a very fundamental obstacle. As Deutsch argued, P cannot be all-encompassing, simply because it cannot explain its own origins. We need a law more fundamental than P, from which P can be derived. But then this more fundamental law also needs to come from somewhere. This is like the metaphor of the painter in the lunatic asylum, who is trying to paint a picture of the garden he is sitting in. He can never find a way to completely include himself in the picture and gets caught in an infinite regression. Does this mean we can never understand the whole of reality? Maybe so, given that any postulate that we start from needs its own explanation. Any law that underlies reality ultimately needs an a priori law. This puts us in a bit of a ‘Catch 22’ situation. So, are we resigned to failure or is there a way out? Is there some fundamental level at which events have no a priori causes and we can break the infinite regression? What does it mean for an event to have no a priori cause? This means that, even with all prior knowledge, we cannot infer that this event will take place. Furthermore, if there were genuinely acausal events in this Universe, this would imply a fundamentally random element of reality that cannot be reduced to anything deterministic. This is a hugely controversial area, with various proponents of religion, science, and philosophy all having a quite contrasting set of views on this. Often people get very emotional over this question, as it has profound implications for us as human beings. Could it be that some events just don’t have first causes? The British philosopher Bertrand Russell thought so. In Russell’s famous debate with Reverend Copleston on the origin of the world, Copleston thought everything must have a cause, and therefore the world has a cause – and this cause is ultimately God himself.