Why would these forms of magic only be able to affect organic/living matter?

Question

Long story short, in Phase One, psions (mages) are rare, and they can:

• Move and shape organic tissue, like flesh, plants or fungus
• Alter the emotions, senses and health of living beings
• Manipulate inks and substances for the purposes of chemistry and journalling
• Get destructive seizures that cause them to do bad things to themselves and others

Then humans defeat an eldritch abomination, and harness it into a new form of psionics. Then, a lot of people:

• Manifest and manipulate a black, organic-looking mass as tendrils, projectiles or prosthetics.
• Quickly "interface" with others, sending thoughts and messages through

Phase Three gets wild, and people figure out how to:

• Create semi-autonomous golems that help build and fight
• Resurrect / golemify dead people

The question is, what in this setting makes psionics unable to shoot lightning, whirl around metals, teleport or go invisible? What keeps it from giving people "X-Men superpowers"? Bonus points for why it can't be used to make people fly ("I'm manipulating my own tissue").

Answer 1

What keeps them from developing superpowers like this are the limitations of the human body. Your psionics can't create a lightning bolt because a human can't generate enough electricity to make a meaningful lightning bolt nor can they generate enough of a magnetic field to manipulate metals.

Likewise invisibility by bending the light around will not work for the same reason. Altering a target's senses (Point 2) so that they will not notice you could be thought of as a form of invisibility, but that is a universal invisibility power and could fail on the canny. For those that are familiar with D&D, this is the difference between the Magic spell Invisibility and the Psionic power Cloud Mind.

Flight is denied by humans not having the strength or muscles to be able to fly by default. While you can very temporarily manipulate organics in defiance of gravity to heal or manipulate flesh properly, you cannot manipulate an entire body to ignore gravity on a whim.

Now there are people that will try to fly and study how to do it -- hollow bones, strong wings, increased musculature, and so on. And they will use the first point (manipulation of flesh) to do this. People will look to the rest of the animal kingdom to learn how they do things and aim to potentially replicate nature's weird powers for fun and/or profit.

Extreme and/or excessive manipulation of the body might result in sterility or other unforeseen effects that mean that people can't pass on their enhancements and powers gained through their psicraft to progeny. Or they can but they are no longer fully human and their powers are limited to ones given to them by their parents -- their psionics are locked into maintaining their form until a certain power level is reached.

TL;DR: In short, your powers are limited to/by the current biologic abilities of whomever you are using them on.

Answer 2

Your psions are masters of orgone.

https://en.wikipedia.org/wiki/Orgone

Orgone was seen as a massless, omnipresent substance, similar to luminiferous aether, but more closely associated with living energy than with inert matter. It could allegedly coalesce to create organization on all scales, from the smallest microscopic units—called "bions" in orgone theory—to macroscopic structures like organisms, clouds, or even galaxies.

This stuff is, in essence, life force. Also growth force and psychic sex force. Read up! Orgone is perfect for your folks because they seem to be doing bio-magic and traditional psionics / telepathy stuff - all stuff of the mind and body. The main guy who devised these theories was a student of Freud and so there is a lot of his stuff in there too - especially the sexual stuff, which I hope will be ok for your fiction. I personally am ok with sexy golems, and have started writing a K-pop style song about one.

As regards flying and teleporting, you just do not have your magic violate the laws of physics. Those laws are there for good reasons!

Answer 3

Taking this at face value, I'd say that this magic specifically affects something related to or containing a specific quality that happens to only be in biological material. This would easily cover why it only really seems to be able to manipulate and alter the properties of certain things over others. For instance, maybe this magic can only embed itself in these materials, or there is already something in these materials that the magic can work on.

As for why it cannot allow people to do something but not others, that is far more of a complex question. After all, the idea of "shooting lightning" or flying could theoretically be achieved by altering the body to have that capacity, just as much as it could be done by manipulating external factors; that it can do neither in these cases implies that it cannot vastly alter the baseline functions of a subject's body.

So going from there, it's pretty easy to see where the limit lies from your examples.

• Moving around and restructuring biological materials.
• Manipulating a body's systems (likely by triggering or inhibiting specific responses)
• Grow more biological material.
• And creating artificial creatures.

None of this requires more than being able to move around certain materials in complex ways and instigating the growth of new materials. Once you can do that, all those other abilities fall into place. Many things can be done just by using that movement to trigger or inhibit specific responses the body already has (alteration of emotions, senses, health, generation of seizures, and instigating specific behaviors). The "interface" ability depends on if it is two ways or not. If it is one way only; then all it takes is one individual to force another's brain to think whatever "message" is being sent to them. If it is two ways, then in addition to that capacity, the sender would have to be able to sense and interpret the other's signals; which isn't a stretch since it would be hard to manipulate their biology without having some feedback to work with.

The other abilities just come from being able to grow biological material. This would help reshape tissue, grow new appendages, or create "golems". However, this implies that what new tissue you can grow is limited to only having common functions (hence the lack of certain abilities like shooting lightning, telekinetically manipulating metals, teleportation, etc.).

Finally, the inability to fly implies that while you can move and manipulate biological material, it cannot be done with a force strong enough to lift something with the weight of a human off the ground (at least long enough to consider it flight).