Mental powers are a staple of both science fiction and fantasy—and even quasi-SF genres like paranormal romance.  The idea’s like the traditional iceberg:  easy to put into a story, but with some major assumptions lurking under the surface.

The Physical and the Non-Physical

In SF, it became fashionable to use the invented term “psionics” to refer to powers of the mind.  The term seems to have originated by analogy to “electronics,” giving it a scientific (or pseudo-scientific) cast, and using the Greek letter psi, the first character of psyche, “soul” or “mind.”  Sometimes simply “psi” is used, as in “psi powers.”  It’s a useful coinage.

There are two broad approaches to psionics.  One treats mental power as acting purely on other minds—what we can loosely call nonphysical:  for example, telepathy.  The other approach allows mental powers to act directly on matter:  the most familiar example is telekinesis, moving things by mind power.

Note that distinguishing “physical” from “nonphysical” already involves some pretty big assumptions—but we’ll get to that.

Mind-to-Mind

Quite a few science fiction stories postulate mental powers that have only mental effects, such as talking mind-to-mind.

The “Lens” worn by the “Lensmen” of E.E. Smith’s classic series is essentially a psionic amplifier.  It gives the wearer telepathic abilities.  This is extremely useful in making contact with unfamiliar species—especially in interstellar law enforcement, with instant communication an essential for “lawmen” that might be pursuing criminals into unknown regions of space.  The Lens also serves as a means of identification that cannot be faked, since an individual’s custom-made Lens will kill anyone who touches it if it’s not in contact with the designated wearer.

But Lensmen can’t make things physically happen by mind power alone; they have to use the conventional space-opera gear of ray guns and such.  The Lensmen can communicate mentally; they can influence or even take over the mind of another person; they can erase or implant memories.  But a Lensman can’t lift objects and throw them around without flexing his muscles in classic action-hero fashion.

There are some odd borderline cases.  The main character, Kimball Kinnison, gains a “sense of perception,” allowing him to perceive nearby objects without using the standard five senses.  He can “see” through solid objects, for example.  That does involve interaction with inanimate matter, of course; but the interaction is all one way—he can’t affect the things he perceives.

Now, a contemporary scientist physicist would find this paradoxical, since it’s fundamental to quantum physics that you can’t perceive an object without interacting with it—bouncing photons off it to see with, for example.  But the Lensman stories were planned out in the 1940s, when we were not so acutely aware of quantum-type theories of perception.  The anomaly does illustrate the difference between these two theories of knowledge:  one in which the knower is the passive recipient of information, and the other in which knowledge is always the product of interaction.

James H. Schmitz’s numerous stories set against the background of the interstellar “Federation of the Hub” use a similar theory of psionics.  Telzey Amberdon, one of the main characters, can communicate telepathically with nonhuman creatures such as her massive “pet,” the crest cat TT (who turns to be a formidably intelligent being in his own right).  Hub psis like Telzey can influence other minds and can be extremely dangerous—whether in a good cause or a bad.  But physical objects aren’t affected.

A similar sort of psionics is assumed in A.E. van Vogt’s classic mutation novel Slan, and in one of my childhood favorites, Star Rangers (The Last Planet), by Andre Norton.  For a more well-known example, the movie Independence Day showed the inimical aliens using mind control to speak through a captive human to communicate with other humans.  But to properly destroy humanity, they used conventional physical weapons.  (Well, “conventional” as science fiction goes; the alien weapons were dismayingly novel for the embattled Earthlings.)

Fantasy, too, can feature purely mental abilities.  There are references in The Lord of the Rings to the ability of elves and wizards to speak mind-to-mind.  (This was shown more explicitly, as I recall, in the movie versions of The Hobbit.)  An analogue might even be found in ghost stories.  Ghosts are often portrayed as acting only through influence on human minds, whether through terror or telepathy—as in A Christmas Carol:  the various spirits do not act except on Scrooge’s own consciousness.

Sometimes telepathy is imagined as “hearing” only what people verbalize—what’s put into words; for example, in Al Macy’s novels about mind-reading detective Eric Beckman.  In other cases, telepathy allows direct access to other people’s feelings and inchoate thoughts, somehow getting behind the speech-forming function.  The notion that one can think without words would itself be anathema to many a twentieth-century linguistic philosopher—consider the linguistic relativism or “Sapir-Whorf hypothesis” so adroitly used in the movie Arrival.  The difference raises basic questions about the relation between speech and thought, and how thinking works.

The divide between mental and physical powers gets further eroded when the story includes telepathic machines.  The Psychology Service in Schmitz’s Hub routinely uses mechanical detectors to monitor psis.  In Slan, “Porgrave broadcasters” can send “recordings” telepathically.  Even aside from the Lens itself, which is a quasi-living physical device, the Lensman series eventually gives us machine-generated mental screens, analogous to the physical force-fields of space-opera lore.  If psionics were confined to minds alone, how can machines handle it?

I’ve spoken loosely about this sort of mind-on-mind power as “nonphysical”; but that involves a very significant assumption—that the mind is not a physical thing.  If the mind were wholly reducible to the brain, there would be no reason in principle why mind powers would only affect matter in the form of other brains.  By analogy, microwaves can be used for communications, but also for cooking dinner.  On this assumption, mind powers would constitute just another kind of physical force, the analogy often being a different “wavelength” of energy.  Second Stage Lensman refers to the “frequency-range of thought” (ch.14), and Smith’s Skylark series presents thought as a “sixth-order wave”—whatever that may be.

Mind Over Matter

We’ve gotten so used to things like telekinesis nowadays that the mind-only abilities discussed above may seem oddly constrained to us.

The original Star Wars film, A New Hope, showed us that the Force could mediate mental communication, even with the dead (“Use the Force, Luke”), and some degree of mind-control or mental influence (“These aren’t the droids you’re looking for”).  But it was only in the sequel that we saw that it could also enable telekinesis.  I still recall the moment when Luke, ice-cemented to the ceiling in the wampaa’s cave, strains fruitlessly to reach his light-saber—then relaxes and closes his eyes; and I thought with some excitement, so, we’re going to get telekinesis too!  By the end of the episode, we’re watching Darth Vader use mental power to throw objects to distract Luke and keep him off-balance.  You can even use this matter-moving power to move yourself, or in effect to fly without wings—as we saw in one memorable scene in The Last Jedi.

By now this sort of mind-over-matter is familiar territory.  But there are still aspects that aren’t obvious on the surface.  For one thing, telekinesis is apparently reactionless.  It’s unclear whether it obeys Newton’s laws of motion, under which action requires an equal and opposite reaction.  It would have been a great comic scene in Empire when Yoda impressively lifts Luke’s X-wing fighter into the air—and Luke had looked over to see Yoda rapidly sinking into the muck, with the entire weight of the X-wing bearing down on his diminutive form.

The simplest fantasy version of telekinesis is the poltergeist, an immaterial spirit which (rather bafflingly) is capable of throwing around physical objects.  Levitation, whether of oneself or of something else, is a commonplace for magicians.  In fantasy, however, mental powers tend to bleed over into magical powers, which we don’t think of in quite the same way—although one way of conceiving magic is as a kind of mind over matter.

There are other kinds of (fictional) mental interactions with matter, over and above mere movement.  A common trope is the ability to start fires, or “pyrokinesis,” as in Stephen King’s Firestarter.  This might be interpreted as a subtle form of telekinesis—since heat consists of motion at the molecular level, maybe a telekinetic could create heat by causing an object’s molecules to move faster.  Such an explanation leaves open the question of where the added energy is coming from; but that’s an issue common to any form of telekinesis.  There may be a certain nerdy satisfaction in supposing that a physically puny specimen like, er, yours truly could throw things around by sheer power of mind, even though one’s muscles aren’t up to it.  But whether things are moving by mind or by muscle, there has to be energy coming from somewhere.

There are other things you can do with matter besides just moving it around.  Julian May’s Saga of Pliocene Exile, and related stories, postulate “metapsychic powers” that include “creativity,” allowing metapsychics to change the form of matter and thus materialize or convert physical objects.  Other stories imagine psionic abilities to “read” the history of an object or a place.

Teleportation—instantaneous movement from one place to another—represents a kind of in-between.  Physical objects are obviously affected, but the physical object in question is typically the practitioner’s own body, and perhaps other objects physically connected (such as clothing—but clothing doesn’t always come along, depending on the story, which can be inconvenient).  Does it count if your mind affects only your own body—the one locus where even theories that sharply separate mind and matter have to assume some crossover between the two?

There’s a long tradition of mental powers in comic books too.  But given the visual nature of the medium, physically effective mental powers tend to predominate over the purely mental.  We do see some of the latter—pure telepathy in Marvel’s Professor Xavier or DC’s Saturn Girl.  But much more popular is Marvel Girl (Jean Grey), whose telekinetic powers make for much more striking imagery.

Minds and Bodies

Considering these two approaches to mind powers raises the philosophical question of whether minds affect matter only in and through a person’s body, or can do so independently.

If we exclude direct physical effects from the scope of (fictional) mental powers, this suggests parallel realms, with thought proceeding on one level while physical actions occur on another, linked only through the minds of humans or other intelligent beings.  It’s almost a Cartesian approach (that is, a theory similar to that of René Descartes) of mind-body dualism, and sinks roots into the long-standing debates over the “mind-body problem.”

The “sense of perception” concept, similarly, functions as if there were two independent metaphysical levels, mental and physical, and this mental sense could allow a person to go “around” the physical senses and inspect an object directly.  The philosophical notion of intentionality (not to be confused with the usual sense of “intentional” or deliberate) is adaptable to such non-sensory knowledge.  But the trend in both philosophy and physics over the last couple hundred years has been to focus on the physical connection between the knower and the known.

It’s become a standard assumption that we can’t know or do anything without a physical connection.  Anything else seems “unscientific.”  What’s interesting is that we seem to be willing to accept the now-unpopular postulate of non-physical knowledge and events when we’re dealing with fiction.

Of course, it’s also possible to meld the two back together by taking the position that mental powers really only reflect physical events taking place at a level we can’t yet detect—as with Smith’s “frequency range.”  But that isn’t the only way to conceive of the relationship.  There is still a certain imaginative appeal, at least, to the notion that mind can act independent of the constraints of the physical body.

I think such stories are helpful.  We’re apt to rush to conclude “science has proven” that the mind equals the brain and the brain is just a particularly subtle form of matter.  Science has not, in fact, proven any such thing.  The physical sciences assume, understandably, that only physics is involved.  But they have by no means demonstrated that all observable phenomena can be wholly explained by physics.  The arguments on this subject are still live.  We should still apply sound standards of evidence, and not leap to conclusions—but that applies in both directions, whether to materialism or to its alternatives.

In other words, there may still be more things in heaven and earth than are dreamt of in our physics, and one of the uses of speculative stories is to help us keep an open mind on these subjects.