Appendix A: Salamancan Authors

Albornoz was professor of law at the University of Mexico. His work on contract law promoted international commerce and advanced just price theory. His Arte de los contractos¹ posited that the exchange of foreign goods is “the most natural [contract] that exists in humanity… buying and selling is the nerve of human life that sustains the universe. By means of buying and selling the world is united, joining distant lands and nations, people of different languages, laws and ways of life. If it were not for these contracts, some would lack the goods that others have in abundance and they would not be able to share the goods they have in excess with those countries where they are scarce." Albornoz is also one of the most outspoken abolitionists from the School of Salamanca and argued that slavery went against “all right, divine and human.” Ultimately, his book was placed on the Index of Prohibited Books by the Holy Office².
1. The Art of Contracts.
2. Formal name for the Spanish Inquisition.

Navarrus’ principal economic work is Comentario¹ (1556), where he denounces price controls and defends money-changing and usury. He is considered to be an independent discoverer of the Quantity Theory of Money. In Comentario he wrote, "Other things being equal in countries where there is a great scarcity of money, all other saleable goods, and even the hands and labor of men, are given for less money than where it is abundant." He also extended this notion to a more general scarcity theory of value, arguing that "all merchandise becomes dearer when it is in strong demand and short supply.”
1. Full title: Resolutory Commentary on Exchanges.

Castro’s work on criminal law produced significant systemic impulses to Hispanic criminal law and he is thus considered “father and founder of [Hispanic] criminal law." His work De potestate legis poenalis libri duo¹ deals directly with the notion of lex² and with the nature and purpose of penalty. He revolutionizes the conception of poena³ and correlates penality with moral blame. Martín de Azpilcueta and Diego de Covarrubias both borrowed from his work.
1. Two Books on the Power of Penal Law.
2. Statutory law.
3. Penality.

Covarrubias y Leiva was the Bishop of Santo Domingo and oidor¹ in Granada between 1548 and 1559. He is famous for leading Salamancan scholars in opposing the enslavement of the natives and was a staunch opponent of Ginés de Sepúlveda. He is widely considered to be the creator of the subjective theory of value, which is the basis of free-market economics. He famously wrote that “the value of a thing does not depend on its objective value, but rather in the subjective estimation of men.” He adds that "wheat in the Indies² has a higher value, although the nature of wheat is the same as in Europe."
1. Appellate judge of the Real Audiencia.
2. The Americas.

Mariana's Historiae¹, though in many parts uncritical, is regarded for its research, accuracy, sagacity and style. Of his other works the most interesting is the treatise De rege et regis institutione². In its sixth chapter the question whether it is lawful to overthrow a tyrant is freely discussed and answered in the affirmative. A volume entitled Tractatus VII. theologici et historici³ containing De morte et immortalitate⁴ and De monetae mutatione⁵ was put upon the Index Expurgatorius⁶, and led to the confinement of its author by the Inquisition. Marjorie Grice-Hutchinson, along with Friedrich Hayek and Murray Rothbard, have maintained that Mariana and the Hispanic Scholastics provided the theoretical basis for the Austrian School of economics.
1. General History of Spain.
2. On the King and the Royal Institution.
3. Seven Theological and Historical Treatises.
4. On Death and Immortality.
5. On the Alteration of Money.
6. The Church catalogue of expurgated texts.

Medina believed that value is increased by the scarcity of a commodity, by the demand of buyers, and by the amount of money available. As Alexander Gallardo notes, "value will increase or decrease according to the scarcity or abundance of the above-mentioned things." The value of money, according to Medina, may also increase because of rarity.

Mercado was born in Spain but was educated and taught in Mexico. He gained fame through the publication of his Suma de tratos y contratos¹, an expanded edition of his Suma de tratos y contratos de mercaderes y tratantes², written as a response to the moral questions raised by traders and businessmen in Mexico and Seville. In his writings, he describes the quantitative theory of money, and although he does not add anything to the work of de Soto or Azpilcueta, he provides a vibrant view of the commercial landscape of the Indies³. Although he also wrote at length about the slave trade and its follies, he was not as vocal as Bartolomé de Las Casas in criticizing the colonial government.
1. Compendium of Deals and Contracts.
2. Compendium of Deals and Contracts of Merchants and Traders.
3. The Americas.

Molina’s most famous work is De Iustitia et Iure¹. There, he explores the notion of price and regulation, always defending the freedom of pricing and advocating for non-governmental intervention in the economy. He actively criticizes price setting as he sees it as a path towards currency debasement. He also defends the charging of interest as an opportunity cost. His career would ultimately lead him to Portugal where he would help advance Late Hispanic Scholasticism at Coimbra.
1. On Justice and Law.

Saravia’s most important work was Instrucción de mercaderes¹ where he attacks any value theory which is based on production, instead insisting that the factors which determine the price of an object are demand, utility, and scarcity. As he notes, “El precio justo surge de la abundancia o escasez de bienes, mercaderes y dinero, como se ha dicho, y no de los costes, trabajo y riesgo”². Grice-Hutchinson confirms that "Saravia denies with considerable vehemence that the cost-of-production can play any part at all in the determination of price... viewing the poor man not as a producer but as a consumer.” Saravia’s work is widely considered a forerunner of modern banking.
1. Instruction for Merchants.
2. “The just price arises from the abundance or scarcity of goods, merchants, and money, as has been stated, and not from costs, labor, and risk”.

De Soto is perhaps Vitoria’s most prolific student and his De Justitia et Jure¹ is widely considered a foundational text in the general theory of international law. Over 27 editions were published in the 50 years following its original publication. Like Vitoria, de Soto condemned the Spanish conquest of the Indies². De Soto was also famous for his analysis of economic issues such as usury, contracts, exchange rates, and just price theory.
1. On Justice and Law.
2. The Americas.

Suárez is known for his work with natural rights and natural law. He is also known as a staunch defender of private property. His work with the notion of pactum translationis¹ helped fuel American revolutions by limiting monarchical power (he opposed the notion of the divine right of kings) and arguing for popular sovereignty via a social contract to which people must consent in order to be ruled. He was most successful in doing so in his Defensio Fidei Catholicae² and De Legibus³. Arguing for the natural rights of the human individual to life, liberty, and property, he rejected the Aristotelian notion of slavery as a natural condition. He criticized Spanish colonization in the Indies in his De Bello et de Indis⁴ and viewed the Indies as sovereign states legally equal to Spain.
1. The transference pact, vesting authority from the community to the ruler.
2. Defense of the Catholic Faith.
3. On Laws.
4. On War and on the Indies.

Villalón is famous for his Provechoso tratado de cambios y contrataciones y reprobación de usura¹ where he evaluates 16th-century commercial practices and inflation in Castile. He also takes a liberal approach towards usury.
1. Profitable Treatise on Exchanges and Contracts and Condemnation of Usury.

Vitoria is widely considered the father of the School of Salamanca. He was a staunch believer in the morality of commerce and believed that natural order is based on the free circulation of people, goods, and ideas. He was an avid supporter of the notion of just price based on scarcity and supply and demand theories. He also helped develop the quantitative theory of money within the School of Salamanca in order to explain inflation in Iberia. He is similarly known as the father of international law because of his lectures, and he wrote at length about the limits to papal and civil power. He rejected medieval ideas of feudalism and universal royal supremacy, and taught that papal power is spiritual and not temporal. He was concerned with the treatment of the natives of the Indies and his work De Indis¹ is perhaps the most extreme defense of their rights. His work on the notion of ius gentium² makes him a forerunner of the concept of the United Nations.
1. On the Indians.
2. The customary law of nations.