Buddhism explains 'existence' using the analogy of a wheel that has twelve components, and the idea is that each component is the effect of the preceding component. The analogy of a wheel entails that there is no recognizable beginning and/or end to the process. Buddhism sees the destruction of this wheel, brought about by some form of interception, as the key to liberation. Given that the wheel does not have any recognizable beginning and/or end, the interception of the wheel can happen at any point, with any of the twelve components. This interception at the level of one component nullifies not only the following component, which is the effect of the cause, but also the preceding component, which is the cause of the intercepted component, by virtue of the fact that the process is cyclical. In other words, interception at the level of B nullifies both C (the effect of the cause B) and A (the cause of the effect B). This shows that causality works "backwards" as well.