Book of Equivalence
Phantom Books
Picture not available

Original Name


Romanized Name

Tōka no Sho




Chapter 3 (light novel 2);
Episode 8


It allows a trade in accordance with the equivalent exchange law.




In Mr. Fieron’s possession

Book of Equivalence is a Phantom Book purchased by Camilla and later used so she could obtain a teddy bear as gift for Dalian. It's present in the Book of Equivalence story.


An old man, owner of a used bookstore, knows about the Black Biblioprincess and her key-keeper. That’s why he sent them a letter requesting their presence when he obtained the Book of Equivalence, although he sold the potentially dangerous item to Camilla as a secondhand book by accident before their visit.[1]


The owner of the Book of Equivalence can get as wealthy as he wishes through a series of exchanges. When he presents an item to barter, the other person will seal the deal with an item of equal value, following the equivalent exchange law. It seems a harmless Phantom Book which ensures fair trades, preventing anyone from being tricked. However, according to Dalian, the Book of Equivalence becomes dangerous since the value of an object is determined subjectively, based on personal judgment. What is worthless to a person, can be precious to someone else. Consequently, the user can be at risk if he desires something deemed as priceless.

If the item is said to be as valuable as life, it’s possible that the Book of Equivalence will bring a tragic fate to its user, seizing his life for the deal, although such event was never shown in the series. As Camilla discovered, the Phantom Book itself can be offered for the exchange. One can escape its spell by handing over the ownership over it. The Book of Equivalence demands a price from its owner, hence its ideal user is the one who doesn’t look for disproportionately expensive things.[1]


Camilla visits the Disward estate to give something to Dalian. She’s ready to open her large bag and show the gift, but the book on Dalian’s knees calls her attention. The Biblioprincess was reading about a long-ended auction, trying to hide her interest for a cute teddy bear. Camilla recognizes the name of the man who bought the valuable toy. She asks Hugh to give her something and leaves the mansion without a word after receiving a red paper clip.

Perennial Wisdom

Hugh and Dalian visit the used bookstore.

Hugh and Dalian have received a letter from the owner of a used bookstore, so they visit the place in the afternoon. The old man had got his hands on a Phantom Book. However, he sold the Book of Equivalence by accident. He describes the buyer, a woman wearing Western clothing. Hugh discovers he’s referring to Camilla. He and Dalian leave the bookstore to find her.

On their way to Camilla’s house, they discuss about the Phantom Book. Hugh thinks its powers would be useful to Camilla’s family business. However, Dalian is concerned because the Book of Equivalence can represent a great danger to its user. They discover she has been moving the entire day, making a series of trades. It was past midnight when they returned to the Disward estate after losing track of her. Dalian is worried about her, since the Phantom Book has the potential of taking her life.

Camilla was waiting for them. She tells Hugh and Dalian how she was bartering to test the powers of the Book of Equivalence. Eventually, she tired herself and decided to head to Mr. Fieron’s place to obtain the teddy bear Dalian wanted. The famous collector was keeping the toy for speculation purposes. He considered the item more valuable than life. Nonetheless, Camilla managed to avoid a tragic fate by offering the Phantom Book itself.[1]

Trivia Edit

  • To test the powers of the Phantom Book, Camilla trades a red paper clip for a pocket watch; then the pocket watch for a fountain pen; then the pen for a cart of oranges; and finally the oranges for a quartz crystal. Hugh and Dalian eventually lose track of her. Later, Camilla reveals that they only tracked half of her exchanges.[1]
    • In the anime, she trades the fountain pen for a crystal ball; the crystal ball for a photographic camera; the camera for a vase; the vase for a necklace; the necklace for a cat; and finally the cat for some oranges. She drops the oranges in the cart of a man before heading to Mr. Fieron's mansion.[2]
  • The ancient Greek philosopher Aristotle discussed about the exchange of equivalents in his economic writings. He said that goods are exchanged fairly only after they are compared and equalized. To do that, it's necessary to analyze the demand and use money as a common measure of value.[3]
    • As Dalian explains, value is assigned by man and it's not inherent in the goods themselves. Aristotle wrote about the subjectivity and relational nature of exchange ratio.[3]
    • Prussian-born philosopher and revolutionary socialist Karl Marx also debates on exchange value, affirming it originated as soon as the means of production became exclusive property of one class and markets formed to sell their commodities. The concept is part of his criticism of capitalism.[4]
  • Equivalent exchange is a recurrent theme in Fullmetal Alchemist, where the practice of alchemy is subjected to the idea that in order to obtain or create something, something of equal value must be lost or destroyed.[5]

References Edit

  1. 1.0 1.1 1.2 1.3 The Mystic Archives of Dantalian light novel, Chapter 3, volume 2.
  2. The Mystic Archives of Dantalian anime, Episode 8.
  3. 3.0 3.1 Edward W. Younkins. Aristotle and Economics. (2005, September 15). In Le Québécois Libre. Retrieved 00:52, June 20, 2017, from
  4. Ken Morrison. Marx, Durkheim, Weber: Formations of Modern Social Thought. SAGE, 2006, p. 87.
  5. Alchemy. In Fullmetal Alchemist Wiki. Retrieved 00:52, June 20, 2017, from