John Dumbleton facts for kids
John of Dumbleton (born around 1310, died around 1349) was an important English thinker from the 1300s. He came from a village called Dumbleton in Gloucestershire, England. Even though he is not widely known today, he made big contributions to logic (the study of reasoning), natural philosophy (the study of nature), and physics (the study of how things move and work). His most important book was called Summa Logicae et Philosophiae Naturalis, which means "Summary of Logic and Natural Philosophy." He probably wrote it just before he died.
Contents
John of Dumbleton's Life
John of Dumbleton became a fellow (a kind of scholar or teacher) at Merton College, Oxford around 1338 or 1339. He studied with other famous thinkers like William Heytesbury, Thomas Bradwardine, and Richard Swineshead. These four medieval scholars were interested in similar topics. They used mathematics and logical thinking to understand nature, theology (the study of religion), and a type of mathematical physics.
It's important to know that their physics was different from modern science. They mostly thought about ideas and used logic, not physical experiments. Because of their focus on math and logic to solve problems, Dumbleton and his friends were called the "Oxford Calculators".
After being a fellow at The Queen's College, Oxford in 1340, Dumbleton returned to Merton College around 1344. He then studied theology in Paris for a short time (around 1345-1347). He came back to Merton College to finish his studies around 1347-1348.
We don't have a complete copy of Dumbleton's main book, Summa Logicae et Philosophiae Naturalis. This makes people wonder if he died suddenly around 1349 before he could finish it.
His Ideas on Philosophy
During the 1300s, many thinkers at Oxford admired the ideas of Platonism (following the ancient Greek philosopher Plato). However, in Paris, the ideas of Aristotelianism (following the ancient Greek philosopher Aristotle) were very popular. John of Dumbleton, who studied in Paris, was influenced by Aristotle.
His book, Summa Logica et Philosophiae Naturalis, explains many ideas found in Aristotle's book Physics. Dumbleton's Summa has ten sections. The ninth section is not finished in any of the copies we have. The tenth section, which was supposed to look at "universals" (general ideas) and "signification" (what words mean), seems like it was never even started.
Even so, the other parts of Dumbleton's Summa are full of interesting medieval ideas. The first section talks about "certainty" and "the psychology of logic." It looks at how we can be sure about what we know.
Most of the book focuses on Aristotle's Physics, On Generation and Corruption (about how things come into being and pass away), and On the Soul. In these sections, Dumbleton discusses topics like:
- How things change (like how motion is measured).
- The features of natural bodies and their shapes.
- Questions about how to classify things (for example, "does light belong to some element?").
- How bodies and shapes move and change.
- The intellect (the mind) and matters of the soul.
It's hard to say why Dumbleton's Summa wasn't more widely known. It might be because it was never finished, or maybe it just wasn't shared enough.
His Scientific Discoveries
The four "Merton Calculators" from Oxford were not just good at philosophy. They also came up with new and important scientific ideas. John of Dumbleton was one of them. He agreed with many of the ideas of William Ockham (1288–1348), especially a rule called Ockham’s razor. This rule says that the simplest explanation is usually the best. This might have helped Dumbleton explain his scientific ideas clearly.
One of Dumbleton's important scientific ideas is worth mentioning. He believed that bodies are finite (they have limits). He suggested that when something shrinks (like condensation) or expands (like rarefaction), no parts of it disappear. Instead, a "denumerable number of parts" (meaning you could count them, even if there are many) always exist. Even though the idea of molecules didn't exist yet, Dumbleton's idea helped to challenge the belief that bodies could be divided into infinitely small pieces.
Dumbleton was also one of the first to show how things relate to each other using graphs. This is like how we use graphs in math today to show functional relationships. He proved the mean speed theorem, which is about how the speed of something changes evenly. He also used this method to study how light gets less bright as you move away from it. He knew it wasn't a simple straight line relationship, but he couldn't figure out the Inverse-square law. That law, which explains how light intensity decreases with distance, was discovered almost 250 years later by Johannes Kepler in 1604.
How We Look at Their Work Today
It's tricky to understand exactly how the Oxford "Calculators" came up with their ideas. They often thought about theorems and theories using abstraction (thinking about ideas without doing experiments). This isn't a criticism just for Dumbleton, but for the whole group of Merton physicists.
One idea is that they might have been trying to create a mathematical picture of Aristotle's view of the world. If this is true, it would explain why they didn't do physical experiments. In other words, the Oxford Calculators focused on using math and logic to understand things, rather than testing them with experiments.
Whether they avoided experiments for religious reasons or because the scientific method hadn't been fully developed yet, John of Dumbleton and his friends should be seen as amazing pioneers in mathematics, physics, and logical thinking.
His Writings
- Summa Logica et Philosophiae Naturalis (around 1349; at least twenty copies still exist)
- Compendium Sex Conclusionum
- Expositio Capituli Quarti Bradwardini de Proportionibus (1332; an explanation of a chapter from Bradwardine's book)
See also
- Medieval European scientists
