Aristotelian Physics and the Dawn of the Scientific Revolution
Aristotle’s Physics: A Two-Region Cosmos
In Aristotle’s cosmos, Earth, motionless, occupied the center, and all other known celestial bodies revolved around it in perfectly circular orbits. In this universe, Aristotle distinguished two regions: the sublunar and the supercelestial.
Sublunar Region
This region is composed of lower, less noble matter: the four elements (earth, water, air, and fire). It is the realm of change and movement; only here do processes of alteration, generation, and corruption (birth and death) occur.
Supercelestial Region
This region is composed of a material different from any known on Earth, which Aristotle called “quintessence”—a fifth element, like fire but incomparably purer than terrestrial fires, which are mixed with other elements. This purest quintessence makes up the stars. In this region, there are no changes; it is incorruptible and eternal. Its only movement is in perfect circles.
Some of these concepts hindered Renaissance science. It was difficult to speak of a single “universe” because matter behaved differently in the two regions, leading perhaps to the idea of a “diverso” or divided reality. The idea that different elements possessed varying degrees of purity and nobility also posed challenges. This cosmos was conceived as having occult qualities, preferred directions, and natural tendencies.
Movement and Nature in Aristotle
The same features are found in Aristotle’s Physics. One of its key concepts is “movement,” defined as the “transition from potency to act“—the process by which a being actualizes the potential inherent in its own nature. This is considered a natural movement. Here lies another idea that the new science would need to discard: that bodies possess a “nature,” an intrinsic way of being that dictates their behavior because their nature requires it. Such explanations served to populate the world with “occult qualities.”
Aristotelian Biology and the Soul
Finally, in biology, Aristotle explained biological phenomena using the concepts mentioned above. Biology was considered only a part of physics. This “nature” in living beings is called the “soul,” but its function is the same: it is the entity that directs or governs the movements and processes occurring within a living being, directed towards a goal.
Persistence of Aristotelian Ideas
Although Aristotle’s system seems odd today, it persisted because it was largely based on common sense and empirical observation. This, combined with the synthesis the Middle Ages created between Aristotle’s thought and Christian doctrine, explains its long survival.
Drivers of the Scientific Revolution
Several factors contributed to the Scientific Revolution:
- The emergence of a new type of philosopher/scientist who did not scorn technical discoveries, such as Leonardo da Vinci. While best known as a painter, he was also a mathematician, mechanic, engineer, and anatomist. Technical knowledge was regarded by Aristotle as inferior to philosophy, which he saw as purely contemplative wisdom.
- The introduction of the mathematical method into experimental research. The principle of inertia (every body remains in its state of rest or uniform rectilinear motion unless a force acts upon it) is not directly observable empirically. In reality, a body on the surface of the Earth eventually stops and does not continue indefinitely in motion due to factors like air resistance, friction, adhesion, and gravity, which prevent the principle from being perfectly observed in everyday experience.
- A great interest in crafts and technical manufacturing processes, including construction, navigation, agriculture, jewelry, watchmaking, lens grinding, glassmaking, etc. The editing and printing of existing treatises on mining, metallurgy, and other technical subjects, thanks to the printing press, gained wider distribution.