Added many links.
Note: This piece is not about the class Charms, and I’ve left aside the vexing question of the difference between Charms and Transfiguration (e.g., why are winged keys a Charm and giant moving chess pieces are a Transfiguration?). Rather, I’m looking at Charms in the general sense, as a synonym for spells, that is, magic in general.
It would also be interesting to compare JKR’s vision of magic to other authors’. However, I haven’t the Comparative Magical Theories background to spend much time on this area. One point I do notice is that unlike in some books, magic in HP is not a matter of wishes or anything so simple; perhaps the characters in books that feature this kind of magic have gotten a hold of a wizard-Charmed object so that for them, all they have to do is make a wish and magical things begin to occur. In JKR’s universe (and this is in fact the very basis for the books, which are structured around an educational system), magic is a talent but also a discipline— technology that one can master only with a great deal of study and hard work. There are other magical universes in which a school for witchcraft and wizardry would be an odd concept.
JKR doesn’t spend much time giving us Magical Theory (maybe Adalbert Waffling’s book will be the next Schoolbook to be released if we ask very nicely); we have to draw our own conclusions from the spells we see. Magic has its own laws. It doesn’t have to fit physics or any other system we know, but it has to be internally consistent. We can believe in an Invisibility Cloak, but if there are then cases where it doesn’t work, we require a plausible a reason why (e.g., a magical eye (GF19), or powers unknown but believable, such as Dumbledore’s as-yet-unexplained ability to see through them (CS14). We can believe that one can conjure useable items out of thin air (e.g., “hundreds of squashy purple sleeping bags” (PA9), “heavy manacles” (PA19), but there must then be a consistent reason why the Weasleys can’t simply conjure up all the things that usually require money (What JKR says about “The Rules” of magic (Accio Quote!)). Even though the laws of magic in the HP universe are seldom made explicit, they have a high level of internal consistency; if they did not, we readers would be finding holes in every chapter instead of the occasional “how does the Fidelius Charm work, exactly?” that surfaces.
Some of the laws seem to be:
- The world is full of naturally-occurring magic aside from that created by humans. There are magical plants (Mandrakes, Devil’s Snare, etc.) and animals (dozens; see FB) as well as magical people. Whether there are any naturally-occurring magical objects is unknown; the books are filled with magical objects, but most seem to be enchanted (e.g. flying Ford Anglia) or created (e.g., the Philosopher’s Stone) by humans. There are many whose magical properties may be human in origin or not (crystal balls, the Mirror of Erised).
- It is not possible to bring the dead back to life (GF36)
- Less definitively, it is not possible to re-ensoul victims of a Dementor’s Kiss (PA12)
Caius Marcius takes up this question more exhaustively in Limitations of Magic.
Spells, at least some of them, behave like physical energy, with forces, counterforces, and vectors much like those seen in physical objects. A spell can be “deflected” and “rebound,” as Voldemort’s attempted Avada Kedavra against Harry in 1981 did (GF33). Two spells can collide like billiard balls: “Jets of light shot from both wands, hit each other in midair, and ricocheted off at angles—Harry’s hit Goyle in the face, and Malfoy’s hit Hermione” (GF18). The storm of Stunning Spells that the Ministry wizards send over Harry, Ron, and Hermione’s heads in the wood after the World Cup create a wind that ripples their hair (GF9). Making magic uses energy as well. “[H]is Patronus was too feeble to drive the Dementor away. All it did was hover, like a semi-transparent cloud, draining Harry of energy as he fought to keep it there” (PA12).
Likewise, there are certain basic elements of magic that are a matter of mechanics: pronouncing words correctly (otherwise, you might end up with a buffalo on your chest, (PS10), learning wrist movements (PS10), adding Potions ingredients in just the right proportions (PA7) and at the right times (PS8). A wand is necessary for most magic.
However, magic is far more than mechanics.
“But that was the easy part, I’m afraid. You see, the word alone is not enough.”
—Professor Lupin (PA7)
The words are just one ingredient of a spell, and there is only so much magic one can learn from books. An intangible and crucial element of most spells is intention, which can even make words unnecessary. Some wand-spells seem not to require an incantation at all (e.g. Snape conjuring up ropes (PA19); the rope-ends then fly to him with a click of his fingers), though this may just be Rowling omitting the incantation because she’s tiring of coming up with a pithy quasi-Latin term every time someone waves a wand. “Accio” is enough to Summon whatever one is thinking of, without the noun; Molly Summons the Ton-Tongue Toffees (GF6) and Harry the Triwizard Cup (GF34) this way. For that matter, intention is key even when one does speak the noun; otherwise, “Accio Firebolt” would bring every Firebolt in the world that isn’t nailed down, but it doesn’t; it only brings the one Harry is thinking of, his own. (GF20)
Even charmed objects will respond more or less strongly depending on the intention of the wizard; Neville’s broom does not at first respond to “Up!” while Harry, who is a natural flier, is unafraid of heights, and has been “looking forward to learning to fly more than anything else,” gets an instantaneous response (PS9). Although Harry’s speculation that brooms, like horses, can sense fear may be tongue in cheek, it is true that Neville’s feelings do not match his words, and his intention to keep his feet on the ground appears to hamper his ability to command the broom. An ability to concentrate one’s mind under stress is therefore very important to making magic.
“Harry—you’re a great wizard, you know.”
“I’m not as good as you,” said Harry, very embarrassed, as she let go of him.
“Me!” said Hermione. “Books! And cleverness! There are more important things—friendship and bravery and . . .”
Another necessary element of many spells is, for lack of a more precise word, character. In some cases the personal element needed is some kind of experience, as with Harry’s struggles to find a memory that is happy enough to make the Patronus incantation effective, since it “will work only if you are concentrating, with all your might, on a single, very happy memory” (Lupin, PA12). In others it is personal qualities such as the independence and will power that enable Harry to resist the Imperius Curse. Less nobly, Harry is stubborn, which also stands him in good stead vis-a-vis Imperius. His inner voice balks at doing something as pointless as jumping onto the desk just on Moody’s say-so: “Stupid thing to do, really . . . . I don’t think I will, thanks” (GF15). Perhaps some spells require downright evil characteristics; for example, perhaps only those who can call upon an inner reserve of sadism can successfully cast the Cruciatus. The intricate interaction of magic and character is crucial to Rowling’s universe; she is writing about Harry’s development, not only into a practitioner of magic, but into adulthood, and his adventures are as much explorations of human experience and emotion and his own deepening character as magical exploits. Otherwise the books would not be nearly so enchanting (pun intended).
Finally, magic requires innate magical ability. It may be that Muggles could wave wands and order broomsticks, “up!” without the slightest response. Some magical objects respond to Muggles—hence the necessity of the Muggle Protection Act, to protect unwary Muggles from enchanted objects such as sugar tongs that will clamp on their noses (CS3, CS4). But others, surely, respond only to a wizard/witch, or else there would be little difference between Muggles and magical folk.
“Take it, or I’ll hex you. I know some good ones now.”
A brief note on hexes, jinxes, and curses. One can hex/jinx/curse both people and objects. Just like “spell” and “charm,” these terms for “not very nice spell” are used more or less interchangeably, though “curse” is generally reserved for very destructive spells such as the Unforgivable Curses. “Jinx” may have a light tone to the Muggle ear (it does to mine), but McGonagall uses the term to describe the things she fears Sirius Black might have done to Harry’s Firebolt (PA11), such as a “Hurling Hex” (PA12), which are far from playful.
Quotes are used like epigrams at the beginning of sections in this essay but since these "epigrams" are in line, so to speak, I am not extracting them from their embedded locations to populate the "Epigram" field.