Category: Medieval Philosophy

Paul of Venice (c. 1369-1429) was an Italian philosopher and theologian who played an important role in the development of scholasticism, the dominant intellectual tradition in medieval Europe. He is known for his contributions to logic, metaphysics, and natural philosophy, as well as his engagement with contemporary debates in theology and politics.

Paul was born in Venice, Italy, and was educated at the University of Padua, where he studied under the famous logician and theologian John of Jandun. He later became a professor of philosophy at the same university, where he taught for many years and wrote extensively on a variety of philosophical and theological topics.

One of Paul’s most significant contributions to philosophy was his work on logic. He wrote several treatises on the subject, including the “Logica Magna,” a comprehensive work on the principles of logic that became a standard textbook in universities throughout Europe. In this work, Paul defended the Aristotelian view that logic is the foundation of all knowledge and argued for the importance of formalizing logical rules and procedures.

Paul also made important contributions to metaphysics, the branch of philosophy concerned with the nature of reality. He was particularly interested in the problem of universals, which was one of the central debates in medieval metaphysics. Paul argued that universals, such as “man” or “horse,” exist independently of the mind but are not separate from individual objects. He also defended the view that the existence of universals is necessary for scientific knowledge and that they are the basis for the classification of objects in the natural world.

In addition to his work in logic and metaphysics, Paul was also engaged in contemporary debates in theology and politics. He was a critic of the Avignon papacy and supported the reform efforts of Pope Gregory XI. He also wrote on the nature of political authority, arguing that rulers have a moral obligation to govern justly and that the power of the state is limited by natural law.

Paul’s contributions to philosophy and theology were widely respected during his lifetime, and his work continued to be studied and debated long after his death. He was an important figure in the development of scholasticism, and his ideas influenced many later philosophers, including John Duns Scotus and William of Ockham.

In conclusion, Paul of Venice was a significant figure in medieval philosophy and theology. His contributions to logic, metaphysics, and natural philosophy were highly respected during his lifetime, and his ideas continue to be studied and debated today. Paul’s engagement with contemporary debates in theology and politics also make his work relevant to current discussions about the nature of authority and justice. Overall, Paul of Venice was an important figure in the development of scholasticism and a notable philosopher in his own right.

Julian of Norwich was an English mystic and theologian who lived in the 14th century. She is best known for her book, “Revelations of Divine Love,” which is considered one of the greatest works of Christian mysticism.

Julian was born in Norwich, England, in 1342. Little is known about her early life, but she was likely a member of the merchant class and may have been married at some point. In 1373, when she was around 30 years old, she fell ill and had a series of intense visions of Jesus Christ on the cross. These visions lasted for several hours and left a profound impression on her.

After recovering from her illness, Julian became an anchoress, a type of religious hermit who lived in a small room attached to a church. She spent the rest of her life in this cell, devoting herself to prayer and contemplation. During this time, she continued to have visions and revelations, which she recorded in her book, “Revelations of Divine Love.”

“Revelations of Divine Love” is a collection of 16 visions and the reflections on those visions. Julian wrote the book in Middle English, making it one of the earliest known works of English literature by a woman. In the book, Julian describes her visions of God’s love and mercy, and her belief that God’s love is all-encompassing and available to all people, regardless of their sins or shortcomings.

One of the most famous aspects of “Revelations of Divine Love” is Julian’s description of Jesus as a mother who nurtures and cares for her children. This was a radical idea for its time, as the image of God as a father was much more common. Julian’s vision of a maternal God who provides comfort and protection resonated with many people, particularly women, and her work has been influential in the development of feminist theology.

Julian’s writing is also notable for its emphasis on the importance of suffering. She believed that suffering could bring a person closer to God, and that it was a necessary part of the spiritual journey. She wrote, “All shall be well, and all shall be well, and all manner of things shall be well,” expressing her belief that even in the darkest moments, God’s love and mercy will prevail.

Julian’s work was not widely known during her lifetime, but it gained popularity in the centuries after her death. Her teachings have been influential in the development of Christian mysticism and have inspired many writers and thinkers, including T.S. Eliot and Thomas Merton.

In conclusion, Julian of Norwich was a pioneering figure in Christian mysticism and one of the most important English writers of the Middle Ages. Her book, “Revelations of Divine Love,” is a profound meditation on God’s love and mercy, and her vision of a maternal God who nurtures and cares for her children has been particularly influential. Julian’s work continues to inspire and challenge people of faith today.

Henry of Langenstein (also known as Henry of Hesse) was a German medieval philosopher and theologian who lived in the 14th century. He is best known for his works on logic, metaphysics, and natural philosophy, as well as his role as a professor at the University of Paris.

Henry was born in Hesse, Germany, around the year 1325. He studied at the University of Paris and became a master of arts in 1352. He later became a bachelor of theology in 1359, and then a doctor of theology in 1362. He became a professor of philosophy and theology at the University of Paris, where he taught for many years.

Henry’s works include a commentary on Aristotle’s Metaphysics, as well as several works on logic, including Summa Logicae. He also wrote a treatise on natural philosophy called Tractatus de Corpore Christi, which dealt with the metaphysical and physical aspects of the Eucharist.

Henry’s philosophy was heavily influenced by Aristotle, as well as by the works of the medieval philosopher John Duns Scotus. He was interested in the nature of reality and the relationship between the physical and the metaphysical. He believed that the universe was composed of both matter and form, and that form was the source of order and structure in the world. He also believed that knowledge was acquired through a combination of experience and reason.

Henry’s views on the Eucharist were controversial, and his Tractatus de Corpore Christi was condemned by the Council of Constance in 1415. In this work, he argued that the Eucharist was both physically and metaphysically the body of Christ, and that the transformation of the bread and wine into the body and blood of Christ was a real and substantial change.

Despite his controversial views on the Eucharist, Henry was a highly respected philosopher and theologian. He was known for his rigorous approach to scholarship and his commitment to the pursuit of knowledge. His works were widely read and influential, and his ideas helped to shape the development of philosophy and theology in the medieval period.

In conclusion, Henry of Langenstein was a prominent figure in medieval philosophy and theology, whose works on logic, metaphysics, and natural philosophy continue to be studied and discussed today. Although his views on the Eucharist were controversial, his contributions to the development of medieval thought were significant, and his legacy continues to be felt in the field of philosophy.

Henry of Oyta, also known as Henry of Langenstein, was a prominent German theologian and philosopher of the late medieval period. He lived during a time of great intellectual and religious ferment, and his writings reflect the complex intellectual and theological debates of the era. Henry was particularly known for his work on logic and metaphysics, and he played an important role in the development of the nominalist school of thought.

Life and Education

Henry of Oyta was born in the village of Oyta in what is now Austria, around the year 1325. He was educated at the University of Vienna, where he studied theology and philosophy. After completing his studies, he became a professor at the University of Vienna, where he taught for many years.

In addition to his work as a professor, Henry was also active in the church. He served as the chaplain to the bishop of Vienna, and he was later appointed as the abbot of the Augustinian monastery of Klosterneuburg.

Philosophical and Theological Work

Henry of Oyta is best known for his work in logic and metaphysics, particularly his defense of nominalism. Nominalism was a philosophical school of thought that rejected the idea of universals, or abstract concepts that exist independently of individual things. According to nominalism, universals are simply names or labels that we apply to individual things based on their similarities. For example, the concept of “dog” is not a real thing that exists in the world; rather, it is simply a label that we apply to individual dogs based on their shared characteristics.

Henry was a leading advocate of nominalism, and he wrote extensively on the subject. His most famous work is his Summa logicae et metaphysicae, a treatise on logic and metaphysics that was widely read and influential in its time. In this work, Henry argues that universals are not real entities that exist in the world, but are simply names or labels that we apply to individual things based on their similarities.

Henry’s work on nominalism was controversial, and he was criticized by some theologians for his rejection of the idea of universals. However, his ideas had a significant impact on the development of later philosophical and theological thought. Nominalism became a dominant school of thought in the late medieval and early modern periods, and it influenced many philosophers and theologians, including William of Ockham, John Duns Scotus, and Martin Luther.

In addition to his work on nominalism, Henry was also interested in the relationship between faith and reason. He believed that reason was an important tool for understanding the world, but he also believed that faith was necessary for understanding spiritual truths that could not be reached through reason alone. Henry argued that faith and reason were complementary, and that both were necessary for a complete understanding of the world and of God.

Henry’s theological work was also notable for its emphasis on the importance of humility and charity. He believed that pride was a major obstacle to spiritual growth, and he emphasized the need for individuals to cultivate humility and a sense of their own limitations. He also emphasized the importance of charity and service to others, arguing that love for one’s fellow human beings was a necessary expression of love for God.

Legacy

Henry of Oyta’s work had a significant impact on the development of philosophy and theology in the late medieval period. His defense of nominalism helped to establish it as a dominant school of thought, and his ideas on the relationship between faith and reason influenced later and John Calvin.

Walter Hilton (c. 1340-1396) was an English mystic and spiritual writer of the late medieval period. He was a member of the Augustinian Order and lived during a time of great religious and social change in England. Hilton is best known for his influential works on the contemplative life and the journey of the soul towards union with God. His writings had a significant impact on the development of English mysticism and influenced later writers such as Julian of Norwich.

Early Life and Education

Walter Hilton was born in the town of Thurgarton in Nottinghamshire, England, around the year 1340. Little is known about his early life, but it is believed that he was educated at the University of Cambridge. He joined the Augustinian Order and spent much of his life as a monk and spiritual director at the Augustinian priory of Thurgarton.

Spiritual Writings

Hilton’s spiritual writings are characterized by their emphasis on the importance of the contemplative life and the journey of the soul towards union with God. His most famous work is The Scale of Perfection, which he wrote in the 1380s. The Scale of Perfection is a guide to the spiritual life that is organized around the image of a ladder or staircase. The book is divided into three parts: the first part deals with the purification of the soul, the second part with the illumination of the soul, and the third part with the union of the soul with God.

Hilton’s other major work is The Mixed Life, which he wrote in the 1390s. The Mixed Life is a guide to the spiritual life that emphasizes the importance of balancing the contemplative life with active service to others. Hilton argues that the contemplative life is necessary for spiritual growth, but that it must be balanced with service to others in order to avoid the pitfalls of spiritual pride and self-absorption.

Hilton’s spiritual writings are notable for their emphasis on the role of grace in the spiritual life. He argues that it is only through the grace of God that the soul can be purified and united with God. He also emphasizes the importance of humility and self-knowledge in the spiritual life, and he warns against the dangers of spiritual pride and self-deception.

Influence

Walter Hilton’s writings had a significant impact on the development of English mysticism and influenced later writers such as Julian of Norwich. His emphasis on the importance of the contemplative life and the role of grace in the spiritual life helped to shape the mystical tradition in England.

Hilton’s works were widely read and translated into other languages. They had a particularly significant impact on the Devotio Moderna movement in the Netherlands, which emphasized the importance of the inner life and the cultivation of a personal relationship with God.

Hilton’s influence can also be seen in the later development of the English Reformation. His emphasis on the importance of the inner life and the role of grace in the spiritual life helped to lay the groundwork for the later Protestant emphasis on personal faith and the direct relationship between the individual and God.

Legacy

Walter Hilton’s legacy is evident in the impact that his writings had on subsequent generations of Christians. His emphasis on the importance of the contemplative life and the journey of the soul towards union with God helped to shape the mystical tradition in England and influenced later writers such as Julian of Norwich.

Hilton’s works continue to be read and studied today by scholars of medieval spirituality and mysticism. His writings are notable for their clarity and accessibility, and for their emphasis on the importance of humility, self-knowledge, and the role of grace in the spiritual life.

Marsilius of Inghen (c. 1340-1396) was a Dutch philosopher, logician, and theologian of the late medieval period. He was a prominent member of the Scholastic tradition and is known for his contributions to the fields of logic, metaphysics, and theology. Marsilius was a contemporary and colleague of other notable Scholastic philosophers such as William Heytesbury and John Buridan.

Early Life and Education

Marsilius of Inghen was born in the town of Inghen in the Netherlands. Little is known about his early life, but it is believed that he received his education at the University of Paris. He studied under the noted philosophers and logicians William of Ockham and Albert of Saxony, and he was greatly influenced by their work.

Contributions to Logic

Marsilius of Inghen’s most significant contributions were in the field of logic. He developed a system of logic that was based on the work of William of Ockham, but which also incorporated elements of the traditional Aristotelian logic. Marsilius’s system of logic was characterized by its simplicity and clarity, and it emphasized the use of ordinary language in philosophical discussions.

Marsilius’s system of logic was known as the “Inghen School,” and it became one of the most influential systems of logic in the late medieval period. He emphasized the importance of using logical principles to test and evaluate arguments, and he developed a set of rules for conducting logical analysis. Marsilius also made important contributions to the field of semantics, and he developed a theory of supposition that was influential in the development of modern linguistic theory.

Contributions to Metaphysics and Theology

In addition to his work in logic, Marsilius of Inghen also made significant contributions to the fields of metaphysics and theology. He developed a theory of causation that was similar to the theory developed by his teacher Albert of Saxony. Marsilius argued that there are two types of causes: efficient causes, which bring about a particular effect, and final causes, which give purpose or direction to the actions of efficient causes.

Marsilius also wrote extensively on topics such as the nature of God, the problem of evil, and the nature of human freedom. He argued that God is the source of all existence and that all things are contingent upon God’s will. He also developed a theory of human freedom that was based on the idea that humans have the ability to choose between different courses of action.

Marsilius’s contributions to metaphysics and theology were influential in the development of modern philosophy and theology. His emphasis on the importance of efficient and final causes helped to lay the groundwork for the scientific method, and his theory of human freedom influenced the work of philosophers such as Immanuel Kant.

Legacy

Marsilius of Inghen’s contributions to logic, metaphysics, and theology were significant and far-reaching. His development of the Inghen School of logic had a lasting impact on the field of logic, and his theory of supposition helped to pave the way for the later development of modern linguistic theory.

Marsilius’s contributions to metaphysics and theology were also influential. His emphasis on the importance of efficient and final causes helped to lay the groundwork for the scientific method, and his theory of human freedom influenced the work of philosophers such as Immanuel Kant.

Marsilius’s legacy is also evident in the impact that his ideas had on subsequent thinkers. His emphasis on the importance of using ordinary language in philosophical discussions helped to pave the way for the later work of philosophers such as Ludwig Wittgenstein.

Albert of Saxony (c. 1320-1390) was a German philosopher, logician, and natural scientist of the late medieval period. He was a prominent member of the Scholastic tradition and is known for his contributions to the fields of logic, metaphysics, and physics. Albert was also a teacher and mentor to several other notable scholars, including Nicole Oresme and John Buridan.

Early Life and Education

Albert of Saxony was born in the town of Rickensdorf, near the city of Meissen in Saxony. Little is known about his early life, but it is believed that he received his education at the University of Prague. He studied under the noted philosopher and logician William of Ockham and was greatly influenced by his work. Albert later went on to teach at the University of Paris, where he became a leading figure in the Scholastic tradition.

Contributions to Logic

Albert of Saxony’s most significant contributions were in the field of logic. He developed a system of logic that was based on the work of William of Ockham, but which also incorporated elements of the traditional Aristotelian logic. Albert’s system of logic was known as the “Saxon School,” and it became one of the most influential systems of logic in the late medieval period.

Albert’s system of logic was characterized by its simplicity and clarity. He emphasized the use of ordinary language in philosophical discussions and argued that philosophical concepts should be expressed in clear and precise terms. Albert also emphasized the importance of using logical principles to test and evaluate arguments, and he developed a set of rules for conducting logical analysis.

Contributions to Metaphysics

In addition to his work in logic, Albert of Saxony also made significant contributions to the field of metaphysics. He developed a theory of causation that was based on the idea that every event has a cause. Albert argued that there are two types of causes: efficient causes, which bring about a particular effect, and final causes, which give purpose or direction to the actions of efficient causes.

Albert’s theory of causation was influential in the development of modern science and philosophy. His emphasis on the importance of efficient and final causes helped to lay the groundwork for the scientific method, which emphasizes the importance of testing and evaluating hypotheses using empirical data.

Contributions to Physics

Albert of Saxony also made important contributions to the field of physics. He wrote extensively on topics such as motion, space, and time, and he developed a theory of impetus that was similar to the later theory of inertia developed by Galileo and Newton.

Albert’s theory of impetus was based on the idea that a moving object possesses a force or energy that keeps it in motion. He argued that this force or energy is gradually dissipated over time, which causes the object to slow down and eventually come to a stop. Albert’s theory of impetus was influential in the development of modern physics, and it helped to pave the way for the later theories of Galileo and Newton.

Legacy

Albert of Saxony’s contributions to logic, metaphysics, and physics were significant and far-reaching. His development of the Saxon School of logic had a lasting impact on the field of logic, and his theory of causation helped to lay the groundwork for the scientific method. His theory of impetus was also influential in the development of modern physics, and it helped to pave the way for the later work of Galileo and Newton.

Albert’s legacy is also evident in the impact that his ideas had on subsequent thinkers. His emphasis on clear and precise language helped to pave the way for the later work of philosophers such as Rene Descartes and Immanuel Kant.

Nicole Oresme (c. 1320-1382) was a prominent philosopher, theologian, and mathematician of the 14th century. He was born in Normandy, France and is known for his contributions to natural philosophy, economics, and astronomy. Oresme is considered one of the most important thinkers of the late Middle Ages and his work has had a lasting impact on the development of modern science and economics.

Early Life and Education

Oresme was born in the town of Allemagne in Normandy. Little is known about his early life, but it is believed that he was educated at the University of Paris. He studied theology, philosophy, and mathematics and became a member of the Franciscan Order. Oresme was a brilliant scholar and his work quickly gained recognition among his peers.

Contributions to Natural Philosophy

Oresme’s most significant contributions were in the field of natural philosophy. He rejected many of the Aristotelian teachings of his time and instead developed his own theories based on observation and experimentation. Oresme believed that the universe was infinite and that the Earth was not the center of the universe. He also rejected the notion that celestial bodies moved in perfect circles and instead argued that they moved in elliptical orbits.

Oresme’s work in natural philosophy was instrumental in paving the way for the scientific revolution of the 16th and 17th centuries. His ideas on the infinite nature of the universe and the movement of celestial bodies directly influenced the work of Galileo Galilei and Johannes Kepler.

Contributions to Economics

In addition to his work in natural philosophy, Oresme also made significant contributions to the field of economics. He believed that the value of a good was determined by its usefulness and scarcity, rather than its cost of production. He also argued that the price of a good should be based on its market value, rather than its intrinsic value.

Oresme’s ideas on economics were influential in the development of modern economic theory. His emphasis on market value and the relationship between supply and demand foreshadowed the work of Adam Smith and other economists of the 18th and 19th centuries.

Contributions to Astronomy

Oresme also made important contributions to the field of astronomy. He wrote a treatise on the astrolabe, a device used for measuring the altitude of celestial bodies. His work on the astrolabe was widely read and became a standard text in astronomy for several centuries.

Oresme also developed a new method for calculating the size and distance of the moon. His method involved observing the apparent size of the moon from two different locations on Earth and using the principles of geometry to calculate its actual size and distance. This method was a significant improvement over earlier methods and became the standard for calculating the size and distance of celestial bodies.

Legacy

Nicole Oresme’s contributions to natural philosophy, economics, and astronomy were significant and far-reaching. His rejection of Aristotelian teachings and his emphasis on observation and experimentation laid the foundation for the scientific revolution of the 16th and 17th centuries. His work on economics and the relationship between supply and demand was influential in the development of modern economic theory. His treatise on the astrolabe and his method for calculating the size and distance of the moon were instrumental in advancing the field of astronomy.

Oresme’s legacy is also evident in the impact that his ideas had on subsequent thinkers. His rejection of Aristotelian teachings foreshadowed the work of Galileo and Kepler, and his ideas on economics influenced the work of Adam Smith and other economists of the 18th and 19th centuries.

Catherine of Siena (1347-1380) was a prominent mystic and theologian of the 14th century. She was born in Siena, Italy and is considered one of the most important figures in the history of the Catholic Church, particularly for her role in the Avignon Papacy and her efforts to reform the Church.

Early Life and Vocation

Catherine was born into a large family of middle-class wool dyers in Siena. From an early age, she showed an intense devotion to God and a desire to live a life of service to others. When she was sixteen, Catherine experienced a powerful mystical experience in which she felt that she had been visited by Christ and called to devote herself to God. She began to spend long periods of time in prayer and fasting, and eventually became a member of the Dominican Order.

Catherine’s spiritual writings, particularly her famous “Dialogue”, which is a record of her conversations with God, reveal her deep spirituality and her belief in the importance of suffering as a means of spiritual purification. She also emphasized the importance of humility and self-denial in the spiritual life, and encouraged others to turn away from the material world and focus on their relationship with God.

Role in the Avignon Papacy

In the 14th century, the papacy was in turmoil. Pope Clement V had moved the papal seat from Rome to Avignon, France, in 1309, and subsequent popes continued to reside there. This period, known as the Avignon Papacy, was marked by corruption and political intrigue. Catherine became involved in efforts to end the schism between the papacy in Avignon and the papacy in Rome, and worked to convince Pope Gregory XI to return to Rome.

Catherine wrote letters to the pope and traveled to Avignon to meet with him in person. Her efforts were successful, and Pope Gregory XI returned to Rome in 1377. However, after his death, the schism continued, and Catherine continued to work for the unity of the Church.

Efforts to Reform the Church

Catherine was also a strong advocate for the reform of the Church. She believed that the Church had become corrupt and that it needed to return to its spiritual roots. She wrote letters to Church leaders, including Pope Gregory XI, urging them to reform the Church and to turn away from worldly concerns.

Catherine’s letters and writings reveal her strong personality and her determination to effect change. She was critical of the clergy and the hierarchy of the Church, and urged them to live up to their spiritual responsibilities. She also called for greater attention to the needs of the poor and marginalized, and emphasized the importance of love and compassion in the spiritual life.

Death and Canonization

Catherine died in Rome in 1380 at the age of thirty-three. She was canonized by Pope Pius II in 1461, and her feast day is celebrated on April 29.

Catherine’s legacy has been significant. She is remembered for her devotion to God, her efforts to reform the Church, and her mystical experiences. Her “Dialogue” has been widely read and admired for its spiritual insights, and her letters and writings continue to be studied by scholars and spiritual seekers.

Catherine is also remembered for her role as a woman in a male-dominated Church. She was a strong and outspoken advocate for women’s rights, and urged women to take an active role in the Church and in society. Her example continues to inspire women around the world to speak out and to work for justice and equality.

In addition to her spiritual and theological contributions, Catherine was also a skilled writer and communicator. Her letters and writings reveal a deep understanding of human nature and a profound compassion for others. Her work has been admired for its clarity, beauty, and eloquence.

William Heytesbury (c. 1313–1372) was a prominent medieval English philosopher, logician, and mathematician known for his contributions to the fields of logic, natural philosophy, and metaphysics. He was one of the leading figures of the Oxford Calculators, a group of scholars at the University of Oxford who made significant advances in the field of mathematics and logic during the 14th century.

Early Life and Education

William Heytesbury was born in the early 1310s in the town of Heytesbury, Wiltshire, England. He studied at the University of Oxford and earned his Bachelor of Arts degree in 1332 and his Master of Arts degree in 1337. He went on to become a fellow of Merton College, Oxford, where he spent most of his academic career.

Contributions to Logic and Mathematics

Heytesbury was a key figure in the development of medieval logic and mathematics. He made important contributions to the fields of propositional logic, syllogistic logic, and the theory of obligationes, a type of logical debate that was popular during the medieval period.

Heytesbury’s work in propositional logic involved the study of statements that are either true or false. He developed a system of propositional logic that involved the use of truth tables, which are tables that show all possible combinations of truth values for a given set of propositions. Heytesbury’s work in propositional logic was a significant step forward in the development of modern symbolic logic.

Heytesbury also made significant contributions to the field of syllogistic logic, which deals with the relationships between propositions that involve terms such as “all,” “some,” and “none.” He developed a system of syllogistic logic that involved the use of diagrams, which helped to make the logical relationships between propositions more visually apparent.

In addition to his work in logic, Heytesbury was also a notable mathematician. He made important contributions to the study of infinity, including the concept of infinite sets and the distinction between actual and potential infinity. He also made significant advances in the field of trigonometry, developing methods for calculating the sine and tangent of angles.

Contributions to Natural Philosophy and Metaphysics

Heytesbury was also a prominent figure in the fields of natural philosophy and metaphysics. He developed a theory of motion that involved the study of impetus, a concept that describes the force that causes a moving object to continue moving. Heytesbury’s theory of impetus was a significant precursor to the modern concept of inertia.

Heytesbury also made contributions to the field of metaphysics, particularly in his discussions of causation and the nature of universals. He argued that there is no necessary connection between cause and effect, and that causation is only a matter of habit or custom. He also developed a theory of universals that rejected the notion that there is a single universal form that is shared by all instances of a particular kind of thing.

Legacy

William Heytesbury’s contributions to logic, mathematics, natural philosophy, and metaphysics were significant and influential. His work in propositional logic and syllogistic logic helped to lay the groundwork for the development of modern symbolic logic. His contributions to the study of infinity and trigonometry were also important in the development of modern mathematics.

Heytesbury’s theories of motion and impetus were influential in the development of modern physics, particularly in the work of Galileo and Newton. His rejection of the notion of necessary connection in causation was also influential in the development of later philosophical traditions, including empiricism and pragmatism.