We tend to think of ‘medieval’ as synonymous with ‘primitive’ but, although many of the beliefs of the Middle Ages have been superseded, the medieval human mind was just as capable as our own of deep and intricate reasoning about the natural world. The 15th century was a staging post in the continuous, but erratic, evolution of scientific thought which began to accelerate in the following centuries to the point at which the scientific approach to problem-solving and its benefits are now widely accepted. Someone who does not accept findings of modern science is sometimes called ‘medieval’ in their outlook, but this is wrongly pejorative of the medieval mind.
Even so, the 15th century in England was a time when belief in magic, witchcraft and the real presence of the Devil were ever-present threats to a physically healthy and spiritually balanced life. God was the Creator of everything and Mankind’s role was to appreciate the awesomeness of His creation and not to question His works. Society was divided into those who fought and governed, those who prayed, and those who laboured, all contributing in their own way to a mutually supportive social network. Prayer was the most appropriate means by which one could come to an understanding of His Creation.
Science tends to progress in two main ways: firstly, meticulous observation followed by insight which develops into a plausible explanation of the observations. A fundamental aspect of modern science is that theories must be consistent with facts: a beautiful theory contradicted by a valid observation must be refined or rejected.
There are three stages in the development of scientific explanations.
Hypothesis: an explanation of observations which is sufficiently coherent to be testable.
Theory: an explanation which is consistent with observations and extensively tested but not necessarily fully accepted under all conditions.
Law: an explanation, often with an equation, which enables predictions to be made, consistent with subsequent observation.
A weakness of scientific development in medieval England was that so many inexplicable features of life were regarded as beyond enquiry and simply accepted for what they were. A fundamental weakness was the lazy intellectual view which attributed absolute wisdom to classical writers such a Pliny, Aristotle, Galen and others. After the destruction of English monasteries and their libraries by Viking raids of the 8th to 10th centuries, the daily work of many monks was to re-copy standard books from the classical world, borrowing these as necessary from European monasteries. This copying of, and reliance on, the ‘wisdom of the Ancients’ had a stultifying effect on scientific enquiry. Theory dominated fact: an observation that did not fit long-accepted theory was presumed to be in error. This cultural attitude persisted well beyond the 15th century.
Science is now a global human activity. Progress thrives through co-operation, communication and the sharing of knowledge. Inventions and ideas were slow to spread across the medieval world because of the rigours and slowness of travel by land and sea. As maritime voyages of exploration ventured further afield in the last decade of the 15th century, the rate of sharing of ideas and discoveries began to accelerate. The printing press, a 15th century invention, greatly helped the spread of ideas. Amongst the most popular printed books after The Bible were herbals which described the curative powers of plants.
In the 15th century the scientific revolution lay in the future, but this would be the product of essentially the same human mind that thought about the natural world within the 15th century context of a mixture of untested scientific hypotheses and religious dogma. Our 15th century ancestors were centuries away from some of the following major developments of science which we now take for granted.
Mathematics and geometry in the 15th century were the most advanced parts of what we now refer to as STEM (Science Technology Engineering, Medicine) because of their inclusion in the quadrivium (arithmetic, astronomy, music, geometry) of the two Universities: Oxford and Cambridge. The Euclidian basis of geometry is logically consistent and requires no metaphysical belief. Similarly, the observed movements of our planetary system can be mathematically explained and predicted. An early medieval legacy to us are the cathedrals and secular buildings erected using principles of arithmetic and geometry together with a practical understanding of forces gained from centuries of experience and handed down through Master architects and masons.
Computation using Roman numerals, a legacy of the Roman occupation of England (1st to early 5th century) was cumbersome: try adding XLVII to DXIV. Harder still try multiplying VI by XII. One solution was the adoption of the Indo-Arabic numeral system and the calculating tool we know as the abacus. This was introduced to European culture by Pope Sylvester II (b. 946-d.1003) who was a gifted mathematician and astronomer and had spent time studying in Granada during the Caliphate of the tenth (Christian) century.
Biology, botany, zoology and ecology were revolutionised by systems of taxonomy (18th century) and the laws of natural selection (19th century) contradicting the received belief that species were invariant since the Creation.
In physics, the laws of motion and of gravity (17th century) provided a robust theoretical basis for the heliocentric model of the solar system, developed in the 16th century, in opposition to the Ptolemaic geocentric hypothesis that had persisted for over one and a half millennia.
The laws of chemical composition (early 18th century) were the result of over a century of accurate experimentation which overthrew the classical hypothesis of four (or five) elements that had persisted for two millennia.
Medicine was transformed by the germ theory (19th century) which replaced the classical miasma hypothesis of disease transmission and led to the widespread application of aseptic surgery (19th century). The development of chemotherapy using single chemical agents (20th century) rather than complex mixtures of herbs and material of animal origin, displaced the ‘doctrine of signatures’ which had been a basis for drug therapy since the first century CE and the ‘four humours theory’ on which much medieval medicine was based. Vaccination (19th century) provided a novel therapy to combat serial killers from the world of micro-organisms: both those well-known, like smallpox, and those yet to appear such as coronavirus.
Geography and the exploration of the Earth were transformed by the invention of accurate, robust clocks (18th century) to improve the safety and reliability of maritime travel which in turn confirmed the hypothesis that the Earth was a globe. Other instruments such as a robust theodolite (18th century) allowed accurate mapping, encouraging the investigation of previously unexplored territory which resulted in the discovery of new knowledge of the natural world. The theory of plate tectonics (20th century) and the discovery and application of radiometric dating of rocks (20th century) have changed our view of the Earth’s evolution and revised the interpretation of creation stories from world religions.
The development of technology was not hampered so much by erroneous theory: by trial and error, if a man-made object was fit for purpose, that was self-evidently proof of the maker’s skill. Clocks became very sophisticated in medieval England. The world’s oldest (1386) mechanical clock is still working in Salisbury cathedral. The earliest 15th century clock (1410) still working is in Prague and crowds gather every day to watch the display when it chimes at noon.
Another area of advanced technology in the 15th century was metallurgy, encouraged by the propensity for warfare and for display. Highly sophisticated armour was made in Europe and the English nobility were good customers. Simple handguns were also developed in the continent and imported into England along with their trained, foreign users who took part in several battles during the Wars of the Roses. England exported tin and lead, mined in Cornwall, presumably for tableware and plumbing since they were too soft for weaponry. Iron was not yet as widely available or as versatile as it would become three centuries later, but a good blacksmith could use his craft to make a range of objects from a horseshoe to plough, a scythe or a sword and hoops for a barrel of wine – the product of another type of technology.
Metal coinage has been in use for millennia but by the 15th century there was a shortage of silver bullion as European mines were depleted of their ores and the existing metal had been traded in exchange for luxury goods from Asia. This led to the increased use of gold for coinage but that too soon ran out. Three consequences followed: a metallurgical process was developed to extract both silver and copper from deep European ore deposits; copper coins were used as a substitute; the search for gold inspired exploration of distant, fabled lands such in as Africa and the Americas, with, in due course, no little success.