Roger Bacon

England 1214-1294

Roger Bacon, also known as the Doctor Mirabilis, or Wonderful Doctor, was born in Ilchester, Somersetshire, England in the early 13th century into a wealthy family, and was exposed to geometry, music, astronomy, the literary classics of the 13th century, and arithmetic early on. (1) When he was older, he pursued higher education at Oxford and in Paris, joined the Franciscans, and went on to work at Oxford, a school run by the Franciscan order.(2)

Beginning in 1247, Bacon devoted significant periods of time to experimental science. According to the Jacques Maritain Center, “he was the most important cultivator of the natural sciences who appeared during the Middle Ages.” (3) He was suspicious of rational deduction, preferring to “confirm experiences.” He carried out several in-depth experiments on light and rainbows, as well as several thought experiments on other topics. (1)

For some years, starting in 1260, the Franciscan Order prohibited its members to publish works outside of the order unless the work went through a detailed process, as a way to prevent the spread of heresy. The order was still fairly young, and it made sense to try to fix these problems internally. By 1266, however, the rule around publishing works had changed, which allowed Bacon to publish his books for the general educated public. (2)

Bacon wrote several works, but the most famous are his “Opus Majus” and the “Compendium philosophiae”. He was a philosopher, and within the Opus Majus he wrote at length about “the relation between theology and philosophy, ... that all science are founded on the sacred sciences, especially on Holy Scripture, [and on] the necessity of studying zealously the Biblical languages, as without them it is impossible to bring out the treasure hidden in Holy Writ.” (2)

The Compendium contained “an important section on his theory of language and translation” which included Bacon's belief that “name and signification are imposed on the present object, and these are opened to past and present on the basis of verbal tense.” Theoretically, this would result in less ambiguity in conversation, or at least less ambiguity if people pay strict and careful attention to how they phrase things. (4)

He also studied optics and alchemy, and was the first European to describe the process of making gunpowder (1). Bacon was the first European to propose the idea of flying machines, although he envisioned flying machines which relied on flapping mechanisms, not the stiff wings used in modern airplanes. This, one might argue, is because the scientists in those time periods had to rely on what observation they could capture at the speed of the human eye, and what those observations indicated was that birds flapped their wings to move forward and to stay up in the air. The observations didn’t capture the thermals (practically invisible to the human eye) that birds of prey used to make flight easier, and they didn’t capture the way that some birds shift between soaring on extended wings and flapping their wings to keep moving.

Bacon also proposed the idea of motorized ships and carriages, which is especially interesting when one considers that the electric motor was not invented until five and a half centuries later in 1760. This meant that Bacon was basing his ideas of motorized carriages and boats off of the types of motors used for watermills and windmills.

Roger Bacon is an excellent example of a man who worked on both the science of this world, experimental science, and the science that deals with the next world, theology. His extensive work in such wide-ranging fields truly earns him the title “Wonderful Doctor”

Works Referenced

1. Roger Bacon: English Philosopher and Scientist https://www.britannica.com/biography/Roger-Bacon
2. Roger Bacon http://www.newadvent.org/cathen/13111b.htm
3. The Experimental Sciences -- Albertus Magnus -- Roger Bacon https://maritain.nd.edu/jmc/etext/staamp3.htm
4. Roger Bacon https://plato.stanford.edu/entries/roger-bacon/

Francesco Lana de Terzi

Italy 1631-1687

Francesco Lana de Terzi was born in Brescia, Italy, in 1631. He joined the Jesuit order in 1647 and studied philosophy and theology in Rome. Then, he was a professor of science and math at Ferrera, until illness forced his return to his hometown.

The Italian Jesuit is famous as the Father of Aeronautics because of his idea to create a flying machine based in (nearly completely) sound science. (1) He planned to use spheres of copper, with vacuums inside, to produce the necessary lift, having calculated the necessary size to sustain itself along with passengers. (1) His design is interesting because it used known, functional, technology of the day with strict mathematical calculations and scientific theories to create a successful design. (1, 3)

However, there were a number of considerations that prevented its construction. Lana de Terzi attempted to respond to these in his book, such as the idea that the riders of the flying machine would be flown into space. (1) Lana de Terzi responded that the weight of the ship would prevent the vacuum-filled balloons from reaching outer space, and that onboard valves would reintroduce air to the spheres and provide the capability of successful landing. (1) As for the claim that his balloons would not stand up against atmospheric pressure, he argued the spherical shape would help to withstand the pressure. This idea is flawed, though an interesting attempt.

However, one of the reasons he was wrong on this point was that he never constructed the machine, and this for several reasons.(4) First and foremost, his vow of poverty. (1) Lana de Terzi had calculated there was no way for him to fund the machine on his own, and consequently was forced to rely solely on theory. (1) One of the more existential issues was the threat to all civilization. (1) He feared such airships could be used to lay waste to cities with impudence, raining down destruction with any manner of projectile. When aircraft actually were created, this fear came to fruition within fifty years, so he was correct to consider the threatening possibilities of flight(1)

It is extremely interesting that we consider him the father of Aeronautics despite all of these considerations and limitations. Lastly, it has been alleged that his ideas were essentially just, reused versions of others’ work. (4) But all of this is fails to see the rest of his work.

His idea for a flying machine was published in a book which was entitled -- in part -- ‘Promodero, wise overseer of some new inventions’ ( A link which contains pdf verison photographed in the original Italian is here https://www.e-rara.ch/zut/content/titleinfo/9958403). (1, 3). However, the idea for constructing the balloon airship only took up only one of the chapters of the volume. The previous chapter was dedicated to the idea of flight similar to that of birds, and between them Lana de Terzi distinguished between heavier than air flight and lighter than air flight. (3)

However, outside of those two chapters, the rest of the book was not concerned with flight at all. Instead, the purpose of the book was twofold: To explain the myriad inventions he had theorized  and to generate attention for his actual scientific work. (1, 3) One of his ideas was to create a language for the blind, which was actually extremely similar to braille despite preceding Louis Braille by over 150 years. His design was groundbreaking because it relied on a series of dashes to communicate the language rather than attempting to stick directly to the traditional alphabet, as the systems of the time did. Much like his idea for flight, the invention was never actually completed, though it is quite a compelling idea. (5)

The scientific knowledge which Lana de Terzi was publicizing was a planned nine-volume work, named Mastery of Nature and Art, to encapsulate the natural sciences and based in certainty through experiments and geometry. (3) He only managed to publish two, though another was published after his death. (3)

He was also interesting because he was trying to change the accepted ideas of the day in regard to ancient philosophers and magnetism. Lana de Terzi wished to have a variety of sources in use, and compare and contrast them rather than assuming a single source will have all the answers. He argued that science was inhibited by unnecessary fixations on particular sources, such as Aristotle. (2) Lana de Terzi’s attitude was that if Aristotle was wrong, as he was bound to be at some point, one must be willing to learn from some other scientist. (2)

Lana de Terzi was not the only scientist with these claims, but rather represented the new trend of scientists who wished to break with tradition where it did not function. In particular, he was frustrated by the idea that materials’ qualities were part of their ‘nature.’ He remarked annoyedly that if you asked nearly any natural philosopher of his day about anything they would say it was simply “such is the nature of that substance… [why does] a magnet draw iron and not straw, and amber draw straw and not iron?’ They reply this is the nature of amber and that is the nature of the magnet.” (2, pg 17). Altogether a circular argument and therefore unhelpful. Lana de Terzi wanted to break from this tradition by examining the actual causes of the world, hence his attempt at a nine volume collection of science.

It is rather sad then, that we remember him for only his airship. While it relied on a new piece of technology, the vacuum pump, it fails to really show what Lana de Terzi wished to do. (1) It shows that he knew how to predict possible issues with aircraft, but it ignores his desire to revolutionize science. Of all his work, we remember one chapter of the one book he created to generate enough publicity to sell his actual science and this one achievement wasn’t even something that he actually accomplished, nor was it necessarily something he wanted to have happen.

Works Referenced

1. Francesco Lana-Terzi, S. J. (1631-1687 The Father of Aeronautics http://www.faculty.fairfield.edu/jmac/sj/scientists/lana.htm 
2. Elements of Early Modern Physics https://books.google.com/books?id=vBH0vBmG61IC&pg=PA163&dq=Elements+of+Early+Modern+Physics+By+J.+L.+Heilbron+#v=onepage&q=lana&f=false 
3. Francesco Lana http://www.newadvent.org/cathen/08772c.htm 
4. The Rational Mechanics of Flexible Or Elastic Bodies https://books.google.com/books?id=gxrzm6y10EwC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q=francesco%20&f=false 
5. Foundations of Opthalmology: Great Insights that established the discipline https://books.google.com/books?id=4kszDwAAQBAJ&pg=PA46&lpg=PA46&dq