The Principle of Universality says that all laws of nature must work the same way everywhere. That is, the laws are objective; it doesn't matter who does the experiment or where, the same results should be produced under the same conditions. In paranormal studies it means that if ghosts exist they are bound under the same laws we are.
Causality states that causes must exist for all effects, and must come before the effects they produce. For example, parents must be born before their children; they cannot be born after them. In Einstein's physics causality holds in all domains of the natural world, but quantum theory allows for violation of microcausality at the (microscopic) quantum level. In our macroscopic world, however, causality holds absolutely.
It is also important to remember that the connection between a cause and its effect must be a legitimate consequence of natural laws. Pseudoscience frequently misapplies irrelevancies (such as simple coincidence) to imply such a connection, then brings in untested (therefore scientifically meaningless) supernatural agents to connect cause and effect. This is one of the major mistakes made by paranormal researchers today.
- Kline, M. 1964. Mathematics in Western Culture. New York: Oxford University Press.