10. Expecto Patronum
The Patronus Charm is used to fend off Dementors. Being the spectral embodiment of its caster's happiness, the Patronus repels the Dementors who thrive on misery and despair.
Proper practice of the Patronus Charm is difficult to achieve since most students fail to put themselves in a suitable state of mind without the actual presence of a Dementor. When Dementors were banned from the Hogwarts grounds, practical study of the Patronus was removed from the Defence Against the Dark Arts course plan. Attempts to use shapeshifters as stand-ins for Dementors have consistently failed to be of any real use.
— from Spells & Charms III, 1976 ed.
One of the best examples of this is the Patronus Charm. Its incantation, Expecto Patronum, is a masterpiece of layered spell-making that channels its wielder's power in the most direct and visible way possible. Expecto Patronum helps its caster will a physical embodiment of his magical power into existence. It creates an autonomous weapon of pure willpower that can home in on its target while its wielder's mind is muddled by the fear that Dementors use to incapacitate their prey.
Lexically, both halves of the charm carry multiple meanings, all relevant and working together towards the expulsion of the Patronus. The etymological Latin origins of expecto that will resonate most clearly for modern users are the most obvious: to expect, to look out, (ex specere). To produce a Patronus, one must expect it to appear. Since this is inherent in all incantations, it need rarely be addressed within the wording itself. The fact that it is in evidence here proves the failsafe nature of this vital protection charm.
The second origin of expecto is the one more specific to this particular charm: to expel from the chest, expectoro. It is likely the wielder's wand is placed right before his chest when the charm is used and therefore this centring of power in that area is most useful, facilitating the focusing of the power that needs to be expelled. The (inherently flawed) assumption that goodness and happiness resides in the heart (pectus) helps the caster concentrate on the positive energy that he needs to produce the Patronus. Such concentration is vital as our only direct channel to the pure and undiluted magic inside us are the very feelings that the Dementors subvert, or attempt to destroy, in order to make our own magic inaccessible to us.
The part of the spell that deals with what we are to expect is unsurprisingly the one richest in connotations. The root of patronum is, of course, the Latin patr, father. The most fundamental reason for this (often overlooked) is that this is a charm that is very much the product of a patriarchal society. The patr is expected to preserve and protect. The fact that the most powerful of gods have often been pictured as great fathers is telling. The father is a symbol of safety, protection, power, and benevolence – precisely the things essential to the creation of a Patronus that knows its purpose.
The father image inherent to the Patronus Charm has the rarely discussed side effect of affecting the strength of an individual Patronus based on the caster's relation to his father or the image of a father. This would explain the much hyped Potter Patronus, cast as it is by a boy who went from direct father worship to a conflicted turmoil of emotions that are all excellent at counteracting Dementor influence and creating a very powerful Patronus indeed. Rather than being a sign of Potter's great magical powers or prowess, his Patronus is a sign of his substantial psychological father issues. Issues that have thus far served him well.
Phonetically, the Patronus Charm is a prime example of an expulsion incantation. Heavily aspirated and semi-aspirated p's and t's interact crosswise to phonologically represent the thrusting forth of the father figure that is the Patronus. . . . The consonant sounds of the two stressed syllables together form phtr, a close approximation of the Latin patr. . . . The final nm can easily be seen as a shortened form of nam, adding to the sense of reverent foreboding, building the expectation implied in Expecto
Considering the amount of guidance and direction inherent in the very wording of this charm, it is a sure sign of the degradation of wizarding kind that so many people these days suffer great problems creating even the faintest wisp of a Patronus. Though considering the lamentable effects of its destructive twin, the Killing Curse, perhaps this too is a blessing, for never has wit been spread so thin over the Wizarding World as today.
— from Phonetic Focus and Conductive Connotations, or Why the Will is Mightier than the Quill by Henry Witherto, 1999
To please the spirits of the Empty Woods,
To fill the fiends that on the merchants fed,
The Rulers ruled to offer Sacrifice;
To ease the calling of the Empty Ones,
To still the waking nightmares they inspired,
They picked a boy of wit and reason dull
And bade his brighter brother bring him forth
Into that deep and dreary Darkened Wood,
Infested with the fest'ring evil sores
That ravage souls and leave but withered cores.
Poor were the boys, no ruling could refuse;
Against their will, without a backward glance,
They ventured t'wards that vile Forbidden Wood;
The elder wept, the younger wondered why,
Then from the dark was heard a ghastly cry.
From every shade, from every beastly bower,
The damnéd Empty Ones came wailing forth
And circled round the boys to break their wits.
In fevered fits they crumpled to the ground,
Both victims of that vicious, searing sound.
But in the Boy where Wit was loosely tied,
There dwelt a sleeping, silent, secret Soul;
Beneath his breast, a shining Knight drew breath
To thunder forth; Avenge his brother's death.
Of passion, power and the heart of Life
Composed, beside himself he stood his ground,
Opposed the Empty fiends with fiery light;
With strength of spirit, like a Phoenix fought
Against the damnéd spirits o'the dirt;
Their foul advance with flame did he divert.
Drew back they did, like Shadows from the Light,
Like Darkness from the bloom of budding Day,
And bowed before the One they could not fight,
Before that Kingly Soul they could not slay.
Thus having won his vict'ry of the Heart,
He settled slowly on a stronger shape
And rose with brain and brawn of brother born.
Then by the Empty Ones an oath was sworn:
To him or his they would not do a thing;
From that day on, was he their Shining King.
— from the Tale of the Shining King, from a seventeenth century manuscript