School of Salamanca in the context of Humanism

Natural law (Latin: ius naturale, lex naturalis) is a philosophical and legal theory that posits the existence of a set of inherent laws derived from nature and universal moral principles, which are discoverable through reason. In ethics, natural law theory asserts that certain rights and moral values are inherent in human nature and can be understood universally, independent of enacted laws or societal norms. In jurisprudence, natural law—sometimes referred to as iusnaturalism or jusnaturalism—holds that there are objective legal standards based on morality that underlie and inform the creation, interpretation, and application of human-made laws. This contrasts with positive law (as in legal positivism), which emphasizes that laws are rules created by human authorities and are not necessarily connected to moral principles. Natural law can refer to "theories of ethics, theories of politics, theories of civil law, and theories of religious morality", depending on the context in which naturally-grounded practical principles are claimed to exist.

In Western tradition, natural law was anticipated by the pre-Socratics, for example, in their search for principles that governed the cosmos and human beings. The concept of natural law was documented in ancient Greek philosophy, including Aristotle, and was mentioned in ancient Roman philosophy by Cicero. References to it are also found in the Old and New Testaments of the Bible, and were later expounded upon in the Middle Ages by Christian philosophers such as Albert the Great and Thomas Aquinas. The School of Salamanca made notable contributions during the Renaissance.

Antonio de Nebrija (1444 – 5 July 1522) was a Spanish humanist. He wrote poetry, commented on literary works, and encouraged the study of classical languages and literature, but his most important contributions were in the fields of grammar and lexicography. Nebrija was the author of the Spanish Grammar (Gramática de la lengua castellana, 1492) and the first dictionary of the Spanish language (1495). His grammar is the first published grammar study of any modern European language.

Nebrija was one of the most influentual Spanish humanists and an illustrious member of the School of Salamanca. His chief works were published and republished many times during and after his life, and his scholarship had a great influence for more than a century, both in Spain and in the expanding Spanish Empire.

Salamanca (Spanish: [salaˈmaŋka] ) is a municipality and city in the autonomous community of Castile and León in Spain, and the capital of the province of Salamanca. Attached to the comarca of Campo Charro, the city lies on the northern half of the Meseta Central, in the western-central part of the Iberian Peninsula, straddling the Tormes river. As of 2024, with a population of 144,458, Salamanca is the 46th-largest city in Spain.

The Iron Age hilltop site of Cerro de San Vicente [es] on the right bank of the Tormes is considered as the first human settlement in the current-day city. By the 3rd century BCE, the urban settlement in the nearby Teso de las Catedrales had consolidated, under the influence of Vaccaei and Vettones. Following Roman subjugation, the indigenous oppidum gradually became the Roman civitas of Salmantica. Little is known of the history of the place after the Migration Period. Christian settlement took hold in the 11th century under Raymond of Burgundy. For much of its history, Salamanca has been a college town linked to the University of Salamanca, one of the oldest in Western Europe, whose germ was founded in 1218 as a studium generale, holding the status of university since 1254. It acquired a great deal of recognition in the 16th century for the intellectual production of the so-called School of Salamanca. In addition, the city has also recently developed as a centre for Spanish-language learning.

Francisco de Vitoria OP (c. 1483 – 12 August 1546; also known as Francisco de Victoria) was a Spanish Roman Catholic philosopher, theologian, and jurist of Renaissance Spain. He is the founder of the tradition in philosophy known as the School of Salamanca, which laid the groundwork for early free-market economics and individual rights, influencing the development of libertarian thought. Vitoria's work on natural law and the freedom of exchange contributed to later Austrian School economists' emphasis on the moral basis for voluntary commerce. Although less known than others of his kind, he has been considered one of the most influential humanists of the Renaissance.

Noted especially for his concept of just war and international law, his defense of individual property rights and the notion of liberty in trade were pivotal in shaping ideas about non-intervention and economic freedom. He has in the past been described by scholars as the "father of international law", along with Alberico Gentili and Hugo Grotius. American jurist Arthur Nussbaum noted Vitoria's influence on international law as it pertained to the right to trade overseas. Later this was interpreted as "freedom of commerce". His emphasis on voluntary exchange and opposition to monopolistic practices foreshadowed later free market economics.

Natural law (Latin: ius naturale, lex naturalis) is a philosophical and legal theory that posits the existence of inherent laws derived from nature and universal moral principles that are discoverable through reason. In ethics, natural law theory asserts that certain rights and moral values are inherent in human nature and can be universally understood, independent of enacted laws or societal norms. In jurisprudence, natural law—sometimes referred to as iusnaturalism or jusnaturalism—holds that there are objective legal standards based on morality that underlie the creation, interpretation, and application of human-made laws. This contrasts with positive law (as in legal positivism), which emphasizes that laws are rules created by human authorities and are not necessarily connected to moral principles. Natural law can refer to "theories of ethics, theories of politics, theories of civil law, and theories of religious morality", depending on the context in which naturally-grounded practical principles are claimed to exist.

In the Western tradition, natural law was anticipated by the pre-Socratics, for example, in their search for principles that governed the cosmos and human beings. The concept of natural law was documented in ancient Greek philosophy, including Aristotle, and was mentioned in ancient Roman philosophy by Cicero. References to it are also found in the Old and New Testaments of the Bible, and were later expounded upon in the Middle Ages by Christian philosophers such as Albert the Great and Thomas Aquinas. The School of Salamanca made notable contributions to natural law theory during the Renaissance.

Luis de Molina SJ (29 September 1535 – 12 October 1600) was a Spanish Jesuit priest, jurist, economist and theologian renowned for his contributions to philosophy and economics within the framework of the second scholasticism.

A prominent member of the School of Salamanca, pioneered a distinctive theory of divine grace and human freedom known as Molinism, which defends human autonomy in the face of divine omniscience.

Francisco Suárez SJ (/ˈswɑːrɛz/; 5 January 1548 – 25 September 1617) was a Spanish Jesuit priest, philosopher and theologian, one of the leading figures of the School of Salamanca movement. His work is considered a turning point in the history of second scholasticism, marking the transition from its Renaissance to its Baroque phases. According to Christopher Shields and Daniel Schwartz, "figures as distinct from one another in place, time, and philosophical orientation as Leibniz, Grotius, Pufendorf, Schopenhauer and Heidegger, all found reason to cite him as a source of inspiration and influence."