Abstraction

"The... man, if you could call that masked thing with the hollow eyes a man, pulled back, and I opened my eyes. 'There,' it said, 'it is done.' It ran a finger along its ceramic skin, smiling. Not that it was capable of doing anything else. 'I am surprised you would part with such a dear memory. You must truly be desperate. Well, no matter, here is your payment. The rate for a greater logos, as agreed upon.' I stared at the thing's porcelain face, at the patterns that danced across it, and knew for all the world that I ought to be angry at it for what it took. But that was just the thing. I couldn't quite remember what it was that it had taken. I took my money and left."

— A Satisfied Customer

WARNING: SOME INFORMATION IN THIS ARTICLE IS OUT OF DATE Abstraction is an Art that deals with the manipulation, extraction, and repurposing of a person's metaphysical properties. These properties, known as abstractions (yes, both the Art and the things it deals with have the same name, deal with it), can be removed from one individual and stored — typically using a piece of art such as a poem, a painting, or a piece of pottery — then later inserted back into another individual. The Art is practiced primarily by the enigmatic Hollow Men, but it also sees use by many others, mostly those involved with the thought-trade or those who use it unconsciously (such as those afflicted by the Whaleman's Creed).

Abstractions

Every abstraction is classified as one of the three following types, in ascending order of typical potency: A Logos, a Pathos, and an Ethos.
Logoi are abstractions that relate in some way to memory or knowledge. A Logos may be a well-kept secret (the better kept, the more valuable), the memory of a first love, or the knowledge of how to tie a knot. They are generally considered the least valuable type of abstraction, simply because of the sheer number each person possesses. However, more potent Logoi, such as forbidden secrets or especially sweet memories, can fetch more coin. Logoi are most easily stored via the written word, such as in a poem or a song. Sometimes, plays or other forms of theater are used for particularly potent Logoi, but they see less use.
Pathoi are abstractions that relate in some way to emotion or feeling. A Pathos could be a person's love, or their gut feeling (a dangerous Pathos to lack). Typically, only the more potent Pathoi, such as the ability to actually feel an emotion, are traded. This is because feelings themselves are fleeting things, and easily generated. Still, when large amounts of them are extracted, they can be potent indeed when all used at once. Most Pathoi are relatively valuable, and do not vary a lot in potency. Pathoi are by far the easiest type of abstraction to store, and can live within almost any type of art. They can even take root in some things that would typically not be considered as art, so long as their owner has enough of an emotional connection to them. Art that generates the emotion tied to the Pathos being stored are typically the best, such as an energetic tune for excitement, or tax forms for abject despair.
Ethoi are abstractions that relate in some way to a person's character. This is a rather abstract description for an already abstract thing, but perhaps a more definitive description would be impossible, due to the wide variation in what exactly classifies as an Ethos. Examples of Ethoi include a person's good name, their relationship with another person — whether it be one of friendship, of love, or of frosty indifference, and perhaps most notably, their name. Ethoi vary widely in value, but that value is almost always rather high... and the price the one having their Ethos Abstracted pays is of equal magnitude. Ethoi are often important parts of the person they are Abstracted from, and thus require equally great works of art to store themselves in. Statues, architecture, and other such works of art with an similar presence to them are the best dwellings for Ethoi, though they don't necessarily need to be huge things.
There is one type of Ethos, however, that cannot be stored thus. Indeed, it is unknown if it can be stored at all, or at all manipulated by Abstraction. This is the name, or Onomos. In fact, names are practically their own classification of Abstraction, and they are only considered as Ethoi by most simply because they fit better in that category than in the others. The purpose and nature of the name has long been debated, but generally it is believed that it somehow defines a person, makes them who they are, even if all other abstractions have been stripped away. Many claim that the name is in fact the vessel for the human soul, or the soul itself. Certainly it somehow keeps a human... well, human, for those who lose their name (such as the Creed-Wracked) soon become something... else.

Application

At its surface, Abstraction doesn't appear particularly useful, but this couldn't be further from the truth. Abstraction is a valuable Art, and one that has seen much creative use throughout history as well as the present day.
All types of abstraction, from the most insignificant Logoi to the most poignant Ethoi, have a place in the great market of minds, the thought-trade. The thought-trade is primarily ruled by Hollow Men, as they have more mastery over both the mercantile arts and that of Abstraction than any other souls. They offer wonderful treasures in exchange for their customers' abstractions, and many a desperate soul has traded away something truly dear to them in order to get out of a debt. Curiously, while they purchase abstractions of all sorts, they prefer Pathoi. And yet, despite their carts laden with Pathos-filled pots and urns — the Hollow Men are quite fond of ceramics. Understandable, given that they appear to be made of porcelain themselves — they are loath to sell any Pathoi at all, be they potent or pathetic. As a result of this, a sort of underground Pathos trade has sprung up, though the Hollow Men do their best to crush it.
The thought-trade is mostly performed with Logoi, hence the name, though lesser Ethoi are traded frequently as well. The thought-trade has also given rise to a new workforce of spies and investigators, who go about snooping about where they shouldn't and learning things that nobody really needed to know in the first place, then turn about and sell that information to Abstractors, right out of their heads. Unfortunately, since they forget the information that they've sold, they often end up searching out the same information again, then grow frustrated when they find themselves unable to remember or comprehend it.
Abstraction isn't solely restricted to its economic uses, however, and it has had its practical uses throughout history and in the present day. For example, the monks of Mt. Taig often riddled their texts with Logos booby traps, with certain passages implanting maddening knowledge into the minds of those who read them. The Stone Men of the Natyaal River also attempted something similar, with warnings on the fronts of their tombs telling all those who read them exactly what awaited them, should they venture below. In the end, however, all their efforts just resulted in some exceptionally informed tomb-robbers. In modern times, merchants are known to arm their safes and lockboxes with potent Pathoi, which instill unmitigated terror in potential thieves.
Additionally, from time to time abstraction has had its place in war. Weaponry filled with anger seems to almost strike out on its own, and always finds its mark. Armor imbued with gladness feels as light as a feather, while still retaining all its protective properties. And who forget the Katul's Abstract warfare during the siege of Aredanie, when pots filled with misery were slung over the city's walls, causing its inhabitants to die of broken hearts? And then during the Taloric Revolution in Yebrask, when Emil Talor won the overwhelming support of the people for his cause by taking the reputation of a hundred of his followers (one of the reasons that the trade of Ethoi is so heavily regulated).
And then, finally, there are the more... bizarre uses of Abstraction. Things which aren't quite explained, yet exist regardless. The Hollow Men seem to have used it to achieve something adjacent to immortality, their bodies being living works of art themselves, filled with all the Abstractions that make up what they are. However, the Hollow Men still lack names, and many have taken this to mean that they are not people at all, but closer to monsters. That does seem to be the case for those who lack names, such as the furious Creed-wracked, who eventually lose everything but their rage, as their bodies and minds morph and twist into something inhuman. Despite this, and the furious (and sometimes dangerous) protestations of the Sledge League, Hollow Men still remain in a position of power, simply because no one quite has mastery over Abstraction like they do. Ex