I recently was reminded of the somewhat archaic term ‘preternatural’ while watching the classic 1963 horror flick “The Haunting.” In this amazing film, a scientist interested in occult matters (including, especially, ghosts) decides to investigate Hill House, a nearly century-old mansion notorious for being cursed with untimely deaths and considered as undeniably haunted. He and several other hand-picked personnel take up residence in the house, and become subject to various terrifying experiences (I won’t include any spoilers here).
The remarkable feature of the film, from my standpoint as a philosopher of science, was the sophistication of the film’s treatment of scientific inquiry through the persona of the ‘ghost-hunting’ scientist. In his attempts to assuage their fears (on the one hand) or dislodge their skepticism (on the other), he engages his fellow residents/subjects in conversation about his goals and methods. He tells them that he is convinced that there is an understandable explanation behind the phenomena, even though that explanation might involve forces or entities previously unknown. These sorts of phenomena he refers to as preternatural. He notes that in ancient times, magnetic phenomena were viewed suspiciously in this way: they were either feared or denied, since no “natural” explanation was known for them. Yet eventually, science was able to account for magnetic phenomena in terms of the notion of a force that acts according to specific laws, and now it is viewed as perfectly “natural.” So the preternatural, in this context, means something at first disturbing and incomprehensible that nevertheless may become familiar and comprehensible once we better understand it through an expanded conceptual awareness. In that sense, the preternatural is distinguished from the supernatural (which means completely outside the domain of natural scientific explanation).
We have been face to face with a very similar situation ever since the discovery of quantum phenomena. Einstein famously called the nonlocal features of quantum entanglement “spooky action at a distance.” Just as ancient people faced with magnetic phenomena often denied them because they had no “natural” explanation, many researchers want to deny that such nonlocal phenomena reflect anything that really exists. This is because such phenomena don’t have what many researchers can accept as a natural explanation, where what is currently viewed as “natural” is referred to as “local realism.”
Local realism boils down to the idea that all influences are conveyed from one well-localized object to another on a well-defined spacetime trajectory (like a baseball going from the pitcher to the catcher). In fact, progress was made in explaining magnetic (and also electric) phenomena when physicists could explain those in terms of what is called a ‘field of force’. This classical notion of a field of force is a ‘local realistic’ one, in that it accounts for the motions of objects under the influence of these forces in a local, spacetime-connected way: the force is carried by a kind of ‘bucket brigade’ through space and time at no more than the speed of light.
However, it is now well known (through Bell’s theorem) that quantum influences cannot be explained through this bucket brigate picture of classical fields. The influence due to a measurement on one member of an entangled pair of quanta is communicated apparently instantaneously to the other, no matter how far away it is.
Many researchers, faced with these results, throw up their hands and say that there can be no natural explanation for the phenomena in terms of real things; that no realistic explanation is possible. Since no self-respecting scientist will dabble in the supernatural, such researchers turn to antirealism: they deny that there is anything physically real beneath these phenomena. In doing so, they assume that ‘natural’ or ‘realistic’ can only mean a ‘bucket brigade’ spacetime process, as described above for classical fields. But perhaps there is an alternative: recognize that these phenomena need not be viewed suspiciously as supernatural, but that they are merely preternatural; and that in order to understand them, we must expand our viewpoint concerning what counts as ‘natural’.
This expansion consists in the idea that there may be more to reality than spacetime, and that quantum theory is what describes that subtler, unseen reality. In this picture, quantum processes underlying the nonlocal entanglement phenomena (and other strange phenomena such as ‘collapse of the wavefunction‘) take place in a realm beneath and beyond the spacetime realm. In fact, collapse is what gives rise to spacetime events. For more on this expanded view of reality, see my new book: