The Rebirth of Science and Medicine in Hellenistic Greece and Rome 

During the 300s BCE all the way to the early first century, Greece underwent a period of scientific and artistic enlightenment. During this era of expansion and economic revival, Greece was destined to make discoveries that would change the world forever. People like Ptolemy and Euclid made advancements in mathematics with the earliest known table of a trigonometric function and the creation of the standard book of geometry. But the largest advancements were made in science, medicine, and astronomy. Although some of the ideas weren’t fully proven until the Renaissance with the Scientific Revolution of the 16th century, they paved the way for a new world of stability and power, not known to anyone before this period. Not many people understand the significance of the ideas and laws that are continuously in use today as a result of Hellenistic science and medicine. Even simple things like a geometry book are presently used, still teaching people the same things it did hundreds of years ago. The result of the scientific thinkers of Hellenistic Greece like Archimedes and Eratosthenes, medical thinkers like Herophilus and Erasistratus, and astronomers like Hipparchus and Aristarchus contributed much to the world as we know it and led to a complete change in the understanding of the universe.

The age of Hellenistic science was an age full of brilliant thinkers and experimentalists, but none got close to the findings of Eratosthenes, including his calculation of the circumference of the earth and the first map of the world. The geographer placed sundials around a hundred meters apart, and used the data to calculate the circumference of the earth to be close to 25,000 miles, which was no more than 200 miles off of the modern calculation. This led to other scientists like Martianus to make other claims about the earth. Eratosthenes also contributed to the first map of the world. The map was the most accurate map of his day, even including degrees of latitude and longitude. His formulation of the map gave people of his day a much better idea of the earth and its geography. These two discoveries and formulations paved the way to the calculations for the exact circumference of the earth by Posidonius and to modern geography. Without his calculations, even explorers like Christopher Columbus would not have thought about venturing west to find a route to India via the Atlantic Ocean. As a result of Eratosthenes’ findings, the “New World” may not have been discovered, and the hundreds of explorers sailing that way wouldn’t have had any hope of finding land to the west.

Another prime example of Hellenistic science and how it changed the world was the scientist Archimedes, who separated the thought that physics was a branch of philosophy by inventing the compound pulley as well as formulating the law of floating bodies, which he accordingly named the Archimedes Principle. Through continuous experimentation and trial and error, Archimedes was able to develop the compound pulley, a tubular screw for pumping water, which draws water upwards as it revolves. This remarkable device gained application throughout the Hellenistic world, as it allowed water to be moved uphill, a process that farmers will use for the next thousand years up to the present. Another of his memorable inventions was the Archimedes Principle, or the law of buoyancy. He stated that any object submerged partially or entirely in a liquid will lose a certain amount of weight, the same amount as the weight of the liquid displaced by the body. This formulation revolutionized the art of ship building, presenting a way to better stabilize floating ships. The beauty of Archimedes’ discoveries is that they had a direct impact on the world of his time. The compound screw gave farmers a way to transport water upwards with much greater ease than prior. The principle that Archimedes developed provided a method of increasing ship stability and of weighing irregularly shaped objects by water displacement. It even describes how ships stay above the water and how submarines, in the future, sink. Archimedes had a lasting impact on the sciences, and although he didn’t know it then, changed the thought of water and buoyancy to the present.

In Hellenistic science, many thinkers began to rethink medicine and how the human body works, especially in the work of Herophilus, who was the first to practice human dissection and investigate the function of the parts of the brain as well as arteries. After migrating to Alexandria, he began to dissect human bodies of executed criminals, the first to do so in collaboration with his younger contemporary Erasistratus (Pomeroy 319). In his dissections, Herophilus was able to investigate the anatomy of the body, which provided the first detailed description of the body and its inner workings. Among the diagrams of Herophilus were thorough accounts of the brain and arteries. In the case of the brain, he was able to distinguish between its parts and the functions they were responsible for. He discretely differentiated between sensory and motor neurons, revealing his great understanding of the nervous system. Herophilus was able to discover that the arteries contain blood alone, rather than blood and air as Aristotle had suggested, as well as identifying their function of carrying blood from the heart all over the body. Further examination of how the body worked fueled the creation of new theories addressing illness. Although these discoveries were not fully appreciated until the 16th century, Herophilus was the first to start disproving the theory of the four humors which the church had relied on for centuries. His diagrams and studies of the brain identified completely new building blocks of the nervous system and new hypotheses about how the brain worked. Importantly, his discovery of the function of arteries laid the foundation for physicians like William Harvey of the 1500s and 1600s, who recognized the circulation of blood via the heart. Not one of his achievements got much attention in his day; nonetheless they increased understanding of the human body by a lot.

Another major medical scientist central to the concept of the human body was Erasistratus, who was one of the first to study physiology and continued Herophilus’ work in rejecting the idea of the four humors. A contemporary of Herophilus, Erasistratus worked in Alexandria, further investigating his works and discovering findings of his own. Primarily, Erasistratus was a physiologist, who studied the structures and functions of the parts of living organisms. In his studies he was able to discover a good deal about the valves of the heart and their function. Erasistratus’ physiological studies were the first to explain the processes of digestion, respiration, and those of vascular systems, which he used to distinguish between arteries and veins (Lindberg 121). Erasistratus also believed arteries to contain pneuma, which stimulated the tiny particles that made up human bodies by transporting fundamental substances throughout the entire body (Longrigg 95). These explanations were incredibly impressive at the time; portions of them still survive and are used to this day. Erasistratus, similarly to Herophilus, opposed the humoral theory of disease, but he did so much more strongly. He condemned bloodletting (bleeding to balance the four humors) as a cure, an idea that the world had followed for hundreds of years (Koletsis). As a result, he was criticized by many. No one at the time understood the extent of these claims, but they changed the face of anatomy nevertheless so that scientists couldn’t go back to the humoral theory. All of these discoveries, along with those of Herophilus, laid the foundation for physiology and anatomy. His careful dissections that he used to research the body paved the way for Galen, a physician who used them to make more investigations almost four centuries later.

The fields of physics, geography, and anatomy were greatly improved upon during the era of hellenistic science, but more major discoveries were made in astronomy, especially by the astronomer Hipparchus. This remarkable man dedicated himself to mathematics and the stars, compiling a catalogue of fixed stars in the sky and producing the Precession of the Equinoxes. Using his findings and the findings of astronomers before him, Hipparchus was able to determine over 850 fixed stars that didn’t visibly move in the night sky, like the north star Polaris (Heath 52). Not only was this a major achievement in 129 BCE, but he was the first one to create a star chart. His work helped many sailors navigate, providing them with a means of telling direction. In addition, one of Hipparchus’ greatest achievements was the development of the Precession of the Equinoxes, which is the phenomena of the rotation of the sky (Heath 52). When creating his star catalogue, he noticed that the star’s positions were shifted from earlier measurements, indicating that it was not the stars that were moving but earth. This discovery of earth’s motion allowed Hipparchus to further describe earth’s movement in ways that had never been done before. He then proceeded to establish the times that major constellations would appear for given locations, and was able to determine the times of solstices and equinoxes (Lindberg 98). These firsts lead the way for other astronomers like Ptolemy or Tycho Brahe to explain other phenomena. Ptolemy, for example, used Hipparchus’ star catalogues and others of his discoveries to propose an astronomy of circles, as well as making accurate predictions of planetary positions (Lindberg 99). Similarly to other scientists, no one in greek society really took notice in his work until the Scientific Revolution in Renaissance England, so he wasn’t celebrated in his day. In the present, people have finally understood his work, and astronomists honor him as one who changed the face of the universe for eons.

Finally, though no less important than Hipparchus, is a man of Samos named Aristarchus. Sometimes called the “Hellenistic Copernicus”, Aristarchus’ astronomical achievements in the Hellenistic Age include his work in heliocentrism and his calculations on the size of the universe. The first of its kind, his suggestion of a heliocentric system in which the earth circles a fixed sun was met with criticism and doubt (Lindberg 95). Even though he believed he was correct, no one of his day accepted his theory, as it conflicted with the ideas of Aristotle, the ideas of the Jews, and those of the Christian church. The view was so opposed, it took another 1800 years for a scientist to fully prove heliocentrism. Although Copernicus is usually attributed with being the first to prove it, Aristarchus was the first to provide the idea. Additionally, this important astronomer gained the first adequate conception of the size of the universe (Koletsis). Prior, nobody really looked beyond the heavens, believing the religious theory that beyond the solar system was the land of the gods and angels. Aristarchus began to question this with his observations of the stars’ immobility, and expanded the size of the known universe far greater than the accepted size. This was not easily accepted either, but again was proven during the 16th century Scientific Revolution. Both of Aristarchus’ hypotheses, although not proven by himself, started the world on a course for space exploration. He was the first to start changing people’s ideas about the status of the earth versus the sun, and the size of what lay beyond. His work never fails to impress, both in his astonishing mathematical and scientific abilities, and in his intellect to think of ideas that rivaled accepted ones.

Every scientist stated in this paper plays a pivotal role in the modern world today. The idea of heliocentrism and Erasistratus' idea that blood circulates around the body sit at the head of all of astronomy and circulatory research. The discoveries and contributions of scientists like Archimedes and Eratosthenes, the research of the physicians Herophilus and Erasistratus, and the observations of astronomers like Hipparchus and Aristarchus opened up a new era to humanity, launching the discoveries of many ideas which are still in use today. The sheer capacity of discovery that was brought about by Hellenistic science and medicine compares to that of even the Scientific Revolution of the English Renaissance. These ideas were used for the next two thousand years, and led to a new period of scientific thought that changed the world forever. If it weren’t for these scientists, who knows when the human body would be understood, or when the sun would rightfully become the center of the universe. We wouldn’t dream about going beyond the stars without these concepts, all of which are taken for granted today and deserve more appreciation.