May 2nd, 2002
Was there a Scientific Renaissance?
(Or don’t read this unless you have lots of time on your hands)
The Renaissance has been defined as a rebirth of knowledge and revival of art and literature originating in Italy in the fifteenth century. This revival led to the revolution in the arts, which had an immense effect on the “understanding of the world of nature”. A revolution in physics and astronomy changed Western cosmology and greatly influenced the development of modern science. “Measurement, observation, experiment and classification” were beginning to be used on a much wider scale. Debus states that the period between the mid-fifteenth and end of the eighteenth century saw an important growth in “cultural and political influence of Western Europe over all other parts of the globe”. It can be said that science gets invented in the Scientific Revolution. The word scientia had long been in use, but it meant something like “knowledge.” There was no notion of a discipline called Science, and no one described themselves as being scientists or scientific. By the early 1700s, there were Academies of Science, and the word “science” had the specific definition we use today.
Fourteenth century humanists developed a new love for nature. Pertrarch (d.c. 1374) and others began to disregard traditional scholastic views and logic, which led to the rise of new observational study of natural phenomenon. They preferred rhetoric and history rather than the more technical “Aristotelian” studies taught in the medieval universities for so long. These new values led to recognition of problems in education resulting in reform of elementary education. Vi Horino da Feltre (1378-1446) opened a new school that placed emphasis on sports, military exercises, music, geography, history and rhetoric. Moral principles and political action were prioritised over the “study of traditional philosophical and scientific subjects”. The influence of this time period can be seen in the works of Eramus (1466-1536) and Juan Luis Vives (1492-1540) who did not think the learning of mathematics were important. Vives disagreed with the study of mathematics stating that it tended to “withdraw the mind from practical concerns of life”. This reformation was not extended to the universities. More and more scholars were beginning to discard the conservatism of the universities however these institutions still remained the centres of “scientific training”. Peter Rasmus wrote of his “misfortune” that his three years and six months at university had made him “[no] more learned in history and the knowledge of antiquity, nor more skilful in eloquence, nor a better poet, wiser in anything”. Rasmus was not alone in his despair and his complaints were not invalid. Oxford and Cambridge maintained official authority of the ancients and the London School of Physicians frowned on innovation. One can argue that the period labelled as “early Renaissance” contributed little to the development of the sciences. University teaching remained conservative and the reform of primary education was “antiscientific”.
Humanism and Classical Literature
The search for and discovery of new classical texts became prominent in the fifteenth century. Individual scholars went about looking for manuscripts of lost authors, for coins, medals; for anything that could give a better knowledge of classical antiquity. Interest in atomism was revived with the discovery of a copy of Lucretius’s (99-55 B.C.) De rerum natura. Ptolemy’s Geography and Celsus’ De medicina were other great finds with the latter being of great influence because of its language and style rather than the medical content. After these discoveries the importance of Greek was sparked; something Roger Bacon had previously emphasised in the thirteenth century. Many scholars, such as Petrarch, were lacking in their knowledge of the language until the arrivals of the teacher Manuel Chrysolorus (d.1415) in Italy and later Gemistos Plethon in 1439. The “Greek revival” affected all academic fields during the fifteenth century and led to the translations of works by Proclus, Galen and Aristotle into Latin. Other texts to be translated during the humanistic movement and to also have an effect on the development of modern science were neo-Platonic, cabalistic and Hermetic works of late antiquity. Particular emphasis was placed on these texts; Marsilio Ficino (1433-1499) was told by the Cosimo de’ Medici to prioritise the translation of Corpus hermeticum (c. 1460). Revival of these mystical and religious works led to more interest in “natural magic” and new observational evidence was sought with regards to nature.
The search for original texts of antiquity happened with the arrival of the printing press, as it was now possible to produce standard texts at a moderate price. The first printed book from Western Europe dates from 1447. Before 1501 the books printed were from old medieval scholastic texts disregarded by the humanists. The first version of Ptolemy’s Almagest, printed in 1515, was the old medieval translation. Later, in 1528, a Latin translation was printed and a Greek version was produced in 1538.
Besides Latin and Greek, the Renaissance saw a growth in the use of vernacular in scholarly fields. There are two reasons contributing to the increased use of vernacular in the sixteenth century. One being national pride, authors writing about their love of the country and its language and secondly the desire to break from the past. This became the base for arguments amongst scholars. Paracelsus was attacked by the medical establishment when he lectured on medicine in his native Swiss-German in 1527. The use of vernacular was also present in mathematics and physics; John Dee composed a preface to the first English translation of Euclid’s Elements of Geometry in Tudor English. He defended this action by explaining the “common folk” may be able to “finde out, and devise, new workes, straunge Engines, and Instrumentes: for sundry purposes in Common Wealth or for private pleasure and for the better maintayninge or their own estate.”
Observation and Experiment
There were calls for totally new medicine and natural philosophy but this was a minority view. Many scholars still clung to ancient philosophy as long as the texts they used were pure. It was only scholastic translations and commentaries of ancient texts they rejected. William Harvey (1578-1657) openly praised Aristotle, while Robert Fludd attacked the ancients but still incorporated their findings into his own work.
Some ancient texts outlined methods of observational science that the scholars admired and hoped to reproduce. Archimedes (287-212 B.C.), Roger Bacon, Peter Perigrinus and Witelo were all admired for their use of observational evidence or their experimental studies. Although such methods were appreciated it was more conventional to consult ancient encyclopaedias written by Pliny the Elder (23-79 A.D.) and others. Scientists did however start to use more observational evidence than they had previously. An academy was founded at Cosenza by Benardino Telesio (1509-1588) dedicated to the study of natural philosophy. Telesio rejected Aristotle and instead used observation to study nature. The words experiment and observation can also be found in the mathematical works of John Dee.
Advancements in Mathematics and Technology
Also to influence the world of mathematics was the new interest in the works of Plato in which he had emphasised the importance of this field of science. Tartaglia (1500-1557) and others did much for the advancement of mathematics by their work in algebra in the sixteenth century as did Napier’s (1550-1617) invention of logarithms. Mathematics was also increasingly used as a tool for interpreting nature and mathematical theories were used to describe motion by such scholars as Galileo. This was moving away from Aristotle’s ideas. The advancement in this subject was due to several factors, namely new editions of Archimedes’ work becoming available, the study of motion initiated by fourteenth century scholars at Oxford and Paris and a revival of Platonic, neo-Platonic and Pythagorean works.
The need for mathematics in the practical arts and technology was beginning to be recognised. Mathematical studies were needed for warfare and navigation. There was great progress in the invention of instrumentation; astrolabes, telescopes, microscopes and better thermometers were all invented during this time period. A new interest in the work of tradesmen was ignited, maybe as move away from ancient scholarly thought of separating the sciences and manual work. In the course of the fifteenth and sixteenth centuries several books began to be published on practical arts and the operations of industries such as mining. Some areas of science progressed because scholars began to study practical processes. Francis Bacon commented in favour of the “practical purpose of science.”
Developments in Medicine, Anatomy and Physiology
The initial relationship between humanists and physicians was less than amicable. Petrarch often spoke against the medical profession due to its intellectual traditions that were derived from Greek and not Roman antiquity. As mentioned earlier, before the arrival of Manuel Chrysolorus, Greek was little known or understood. It had become common for physicians to take a doctorate in medicine and also in natural philosophy. Galen had previously referred to himself as a philosopher so this was not something new to the Renaissance. Petrarch made public his views that physicians cannot also be philosophers by stating “How can I believe you are a philosopher when I know that you are a mercenary mechanic?” He also believed that medicine should be an art of deeds rather than words as he viewed it as one of the lower mechanical or practical arts. Despite this however physicians showed a growing interest in humanistic activities. At the end of the fourteenth century a physician wrote to a leading humanist of that time, Collucio Salutati, concerned with Petrarch’s views about the inappropriateness of a physician to show such interest in eloquence. Salutati replied “I do not think that your profession should be deprived of the ornament of good language. Indeed, I urge you and [all] physicians to this fluency of speech and to the vigorous pursuit of eloquence,” also adding that these new found skills would not benefit them professionally but only as human beings. By the 1490s physicians themselves began to attack scholastic medicine as they claimed that Arabic physicians and their Italian followers had dragged the medical heritage of the ancient Greek down into “darkness and barbarity.” By this stage a better understanding of Greek and the spread of the humanistic movement to other subjects such as natural philosophy and mathematics meant that humanistic methods could be a tool for the medical profession and its teaching. Nicolo Leoniceno (1480-1524), a medical graduate of Padua, greatly influenced medicine with his humanistic credentials. Leoniceno wrote of the importance of a physician to have the ability to communicate therefore avoiding errors made by Arabic and medieval authorities who had failed to give diseases, herbs and anatomical structures their Greek names. This was a contradiction of Petrarch’s opinion that medicine is an art of deeds rather than words. Erasmus agreed with Leoniceno’s view and stated, “In hardly any other art is error more dangerous, whence…I think that in the future medicine will be considered reprehensible without this [foundation in Greek letters].” By the mid fifteenth century the “rebirth of medicine” had been achieved with Leoniceno cited as a saviour of medicine from “the lower regions.” By now, not only had Arabic and other scholastics been denounced but also the whole range ancient medical texts of antiquity had been translated including the publication of the complete works of Galen in 1541-1542. This led to an emergence of a great number of followers of Galen in the medical profession opposed to those who still subscribed to Aristotelian philosophy. The publication of Galen’s On the teachings of Hippocrates and Plato (De placitis), in which he put forward anatomical and vivisectional evidence to support his proposed physiological system and reasoned against Aristotle’s conclusions that had been derived from deductive reasoning alone. Those that had been previously against Galen could no longer dispute that Aristotle’s ideas were wrong in light of new evidence. This didn’t mean however that Aristotle lost authority; physicians such as Andrea Cesalpino (1519-1603) still defended him though this was a rarity.
Galen’s anatomical and physiological works were most important for his examination of the spinal cord, the mechanism of breathing and the cardiovascular system. His discoveries however were based largely on animal and not human dissection introducing errors into his work. Discovery of these mistakes led to new ideas with regards to blood flow. Galen had suggested that the blood originated in the liver and travelled to the right ventricle of the heart. He also hypothesised the existence of pores between the right and left ventricles of the heart through which a small amount of venous blood moved to the left cavity. It would be some time and a revival in public dissection in the fourteenth century before this error was refuted. Andreas Vesalius became aware of these errors and sought to portray the anatomy correctly. Leonardo Da Vinci had previously done this but his unpublished works brought no attention. Galen was a leading influence in Greek anatomy and physiology and ancient physicians had relied more on his works than their own research. Even Vesalius writes:
“The septum is formed from the very densest substance of the heart. It abounds on both sides with pits. Of these none, so far as the senses can perceive, penetrate from the right to the left ventricle. We wonder at the art of the Creator which causes blood to pass from right to left ventricle though invisible pores.”
This shows the authority that Galen still had in the mid-sixteenth century. “Observation is rejected in favour of authority”. Later Vesalius would reject Galen’s hypothesis and change the thoughts on blood flow much to the criticism of the more conservative. Vesalius’ list of successors includes William Harvey who was learned on his teacher Hieronymus Fabricius’ work on the valves in the veins. Harvey was a self-proclaimed Aristotelian and Galenist. For him, the valves proved that the circulation of the blood was a one-way system. Harvey concluded:
“I began to think whether there might not be a motion, as it were, in a circle. Now this I afterwards found to be true; and I finally saw that the blood, forced by the action of the left ventricle into the arteries, was distributed to the body at large, and its several parts, in the same manner as it is sent through the lungs, impelled by the right ventricle into the pulmonary artery, and that it then passed through the veins and along the vena cava, and so round to the left ventricle in the manner already indicated. Which motion we may be allowed to call circular, in the same way as Aristotle says that the air and the rain emulate the circular motion of the superior bodies; for the moist earth, warmed by the Sun, evaporates; the vapors drawn upwards are condensed, and descending in the form of rain, moisten the earth again…”
He went on further to equate to the beginning of life, using macrocosm-microcosm analogy. He also pointed out that the flow of blood was always towards the heart due to the observation of the valves in the veins. His work was not immediately approved by everyone; conservative authors rejected his book. However he did receive a great deal of support from others, some who saw his work as proof of deep mystical truths. Ancient texts were still not totally rejected but just corrected for errors.
Scientific Illustration and Classification
Advancements in anatomy were made due to an increased level of communication; exact nomenclature was used to move away from confusing Arab-Latin tradition. Another factor effecting this progress was the naturalistic movement in art, which produced works such as Albrecht Durer’s rhinoceros and Hans Weiditz’s illustrations for Otto Brunfel’s Living Images of Plants (1530). The superficial anatomy of the human body had been studied previously by Italian sculptors such as Michelangelo, Raphael and Leonardo Da Vinci but more detailed works showing contents of the body contained many errors. He did perform some dissections but many of Da Vinci’s works were drawn from ancient texts rather than observation and he also drew mechanical models of the body’s functions. Lack of classification and the secrecy around his drawings prevented them having much influence on his successors. Naturalism was to affect the student as much as the artist, both used the same techniques of image reproduction. The anatomist needed the skill to present what he observed. This saw the dawn of an era in which recorded and observational science came into play. This again showed that the anatomy observed didn’t correlate to Galen’s hypotheses.
Scientific illustration would also benefit the fields of botany and zoology. The early sixteenth century saw a reunion between artist and botanist. There was a enduring interest in herbs of medical worth and this produced many texts dealing with this subject called herbals. The discovery of new plants and the recognition of their active ingredients led to the need for more accurate representations. Texts of the humanists and woodcuts from medieval times were not adequate started a new trend in herbals which contained illustrations drawn from nature. The text however didn’t improve and ancient works remained the most popular herbals until Pierre Mattioli (1501-1577) updated Dioscorides’ work. Mattioli’s new editions contained distillation processes for the extraction of the pure and active part of the herb.
The mass discovery of new plants led to the problem of classification. Plants had been alphabetised or placed into groups such as “sweet smelling, purging; venomous, sleepy and hurtful and their counterpoisons; wounds herbs, cooling, hot and sharp; thistles,” and so on to a total of seventeen categories. It wasn’t until Gaspard Bauhin divided Pinax into twelve books do we see a classification system similar to ours today. Further work by Carolus Lonnaeus (1707-1778) brings us even closer to modern classification.
A humanistic impact is once again seen when astronomy during this period is studied. New discoveries were made and new interpretations led to development in this area.
Until the Renaissance, the accepted theory of planetary motion placed the Earth in the centre of the Solar System. The Catholic Church decided to adopt the Ptolemaic model as the proof of the nature of divinity. The Ptolemaic model, a revision and expansion of Aristotelian cosmology, showed the heavens working in a way that seemed divine. It made use of perfect circular orbits and encouraged the belief that the sun, moon, and stars were perfect unchanging bodies. The placement of the earth at the centre of the known universe, confirmed, in the eyes of the theologians, that human beings occupied a very special place in the universe; that God had placed us in a unique position. Theologians used the Ptolemaic model to support Christianity, and looked at any criticism of the model, as a criticism of God, himself.
The Scientific Revolution has already been noted as a return to and study of ancient sources. Amongst Aristotle and Galen, old Hermetic texts were also studied and the cosmology in these is evident in the work of Ficino and a revival of the Aristotelian system has been described in works by Girolamo Fracastoro (1478-1553) In 1538. Despite these influences the Ptolemaic system seemed most popular. Copernicus’s model looked very much like the Ptolemaic model, except that the Sun and the earth had switched places. Rather than locating the earth at the centre of the model, Copernicus located the sun at the centre. Where the sun had been located between Venus and Mars, he had put the earth, with the moon orbiting around the earth. Another difference was that while Ptolemy used epicycles to explain “retrograde motion in his model”, Copernicus used epicycles only to account for the “differential rates of the various planetary orbits.” “In essence, Copernicus used epicycles to make circular orbits mimic the observed effects of an elliptical orbit”. The basic concepts of his system were published in his book De revolutionibus orbium coelestium (1543). While the Copernican model had no major flaws, it’s ability to predict the positions of the planets, Sun, moon, and stars, was no better than that of the Ptolemaic model. As a result, science was left with no objective reason to choose one model over another. Controversy developed, but it was going to take a lot more information before the heliocentric model would replace the Ptolemaic model. Some of the information needed to confirm the heliocentric model came from the observations Tycho Brahe. Brahe made daily observations of the Sun, moon, planets, and stars from an observatory that was custom built for him. He set out to find stellar parallax but could not find it. Brahe actively opposed the Copernican system and proposed his own system. Brahe’s model was a compromise between the heliocentric model proposed by Copernicus and the geo-centric model proposed by Ptolemy. Brahe’s model placed the Earth at the centre of the universe, with the Sun orbiting around the earth. However, none of the other planets orbited the Earth but instead orbited the Sun.
After sending a copy of his book to both Brahe and Galileo, Kepler joined the staff of Tycho Brahe. Kepler’s diligence and ability impressed Brahe so much that upon his death, he left his thirty years worth of observations in Kepler’s hands. With this information, Kepler went on to solve the perpetual problem of planetary motion, the differential rate of a planet’s orbit. Kepler became involved in this pursuit shortly after Brahe’s death, when he took it upon himself to try to mathematically explain Brahe’s observations of Mars’ orbit. Kepler was an early subscriber of Copernican theory, but quickly became perplexed when he could not make the heliocentric model account for Mars’ motion. After several different approaches, Kepler abandoned the idea of a perfectly circular orbit. This shift quickly led him to his three laws of planetary motion:
1) A planet moves on an elliptical orbit wit the Sun at one focus.
2) A planet moves so that an imaginary line connecting the planet to the Sun sweeps out equal areas in equal intervals of time.
3) The squares of the sidereal periods of the planets, P are proportional to the cubes of the semi-major axes of their orbits, a.
These laws revolutionised astronomy and led to the confirmation of the heliocentric theory. His work however was buried amongst philosophical speculations and it was not used by scholars as a basis for planetary theory until the mid-seventeenth century. In the meantime new developments were being made by Galileo Galilei, which helped speed up the acceptance of Copernican theory.
The invention of the telescope in the first decade of the seventeenth century brought the attention of the Christian world back to the heliocentric theory. In 1609, Galileo improved the quality and magnification of the telescope first invented in 1608. With the instrument, Galileo made a number of discoveries that refuelled the debate over Copernicanism. Amongst his findings were the phases of Venus and the satellites of Jupiter. He also discovered that the planet Mars showed changes in brightness and size and that the surface of the sun exhibited dark spots that appeared and disappeared at irregular intervals and moved in a way that indicated rotation of the sun about its own axis. As well as these great observations, Galileo contrasted the Ptolemaic and Copernican systems in his book, the Dialogue on the Two Principal World Systems (1632). The book used logic to argue for the heliocentric model but was only allowed to be published if it presented this system as a hypothesis. Galileo failed to adhere to this and was brought to trial by the Inquisition and forced to make a public confession that his observations were pure fiction. He was confined to his villa in Arcetri for the remainder of his life where he published new works which became the basic for the works of Isaac Newton and an essential base for the development of modern mechanics.
Study of the period between fifteenth and the end of the eighteenth century show a steep increase in the development of science. There was a great influence of humanism during this period, leading to revivals of the works of Ptolemy and Galen, which led to new discoveries by Harvey and Copernicus. Recovery of mystical texts also had a great influence leading to a growing interest in natural magic, astrology, alchemy and other similar fields. This period also showed a change in scientific thought. Observation and increased use of experiment changed the way science was conducted. However, scholars still relied on ancient authorities first and foremost. The development of Renaissance art also contributed to science through better scientific illustrations. Like the literary humanists, the scholars during the Renaissance revered the ancient authorities but went on to diminish their teachings with their own findings.
1. Allen Debus, Man and Nature in the Renaissance, 1978
2. H. Floris Cohen, The Scientific Revolution, 1994
3. A. R. Hall, The Revolution in Science 1500-1700, 1983
4. S. Shapin, The Scientific Revolution, 1996
5. J. W. Shirley & F. D. Hoeniger (eds.), Science and the Arts in the Renaissance, 1985
Posted at 12:15 am | 2 comments | Category: Essays, Science