Passage one is identified as a quote from Book Seven of Plato: The Republic. More specifically, this passage is explaining the Allegory of the Cave, which had the purpose of ‘comparing the effect of education and the lack of it one our nature’ (‘Plato On: The Allegory of the Cave’).
This specific passage is a part of a Socratic Dialogue, written by Plato, around 375 BC (‘Plato: The Internet Encyclopedia of Philosophy’).
An allegory is a story, poem, or another type of writing that one can examine more closely to reveal a hidden meaning(‘Plato On: The Allegory of the Cave’). This quote, at face value, tells us that people are living, imprisoned in a cave. All of their knowledge, whatever the topic, comes from the shadows that appear on the cave walls due to an unseen puppeteer casting shadows. Because this is all that the cave people have ever known, they perceive everything they observe to be real, and that studying and talking about these shadows means they will have a successful and knowledgeable life.
However, a day comes when one can make their way out of the cave and into the sunshine. At this time, a realization occurs that there is more than they had previously known; there are colours, textures, sunlight, none of which the shadows revealed. With this knowledge, he returns to the cave, only to be thought of as ‘crazy’ due to the obscurity of what he is explaining to those who only know the shadows.
If one is to examine the deeper meaning of the allegory and the passage, it explains the cave is our daily and current knowledge. The chains keeping the cave people inside represent the limit on our knowledge that occurs by not studying philosophy, questioning, or searching for more. As the cave people trust what they see on the cave walls to be real, we trust all of what we see or what we are told as real, truthful, and of value. We are chaining ourselves to a ‘cave’ of uncertain knowledge due to not questioning or searching for more. The screen that hides the puppeteer represents our society.
From a young age, we are continually told information that we grow up to believe without a doubt. For example, this information could be that Santa Clause is real or that being a CEO makes your job a valuable one. The hidden meaning of this allegory is that the world of appearance is genuinely not a source of knowledge, which is also Plato’s famous overall philosophical claim (Ray, ‘Revolution Western Science,’ 2020). If we never questioned or critically thought about these claims, we would never release ourselves from the chains of societal puppetry.
Plato, who is Socrates’ most famous student, was learning from him between the years of 470-399 BCE (Ray, ‘Revolution Western Science,’ 2020). Thus, most of what we know about Socrates comes from Plato’s dialogues, in which Socrates is featured as a prominent character (Ray, ‘Revolution Western Science’, 2020). Without directly saying the character who leaves the cave is Socrates, many parallels lead one to believe he is the man in the allegory.
When the man who went outside used intellectual bravery to explain the vastness and complexity of what he saw to the others, they plotted to kill him. Socrates, similarly, was executed for his intellectual bravery, which included being a ‘martyr for free speech and freedom of thought’ (‘Why Was Socrates Killed’). Like the knowledge gained by going outside the cave, Socrates gained knowledge as he studied philosophy and was the first moral philosopher, and following the allegory of the cave plot, inevitably led to his death (Wilson, ‘The death of Socrates,’ 2007).
This passage is part of Galileo Galilei’s 1632 Dialogue Concerning the Two Chief World Systems, the two chief world systems being the church-favoured Ptolemaic System, and the controversial Copernican System. The passage comes from the second day of the dialogue and is spoken by Salviati, a character who represents the views of Galileo (‘The Second Day’).
Before the publication of this passage, Galileo’s trials and tribulations have their roots in the year 1610, the year that Galileo published descriptions of telescope views directly supporting the Copernican Hypothesis put forth by Nicholas Copernicus. In 1616, Galileo’s observations and support of the Copernican Hypothesis were opposed by the Catholic Church. Due to this opposition, the Inquisition, a group organized by the Catholic Church, stated heliocentrism ‘to be formally heretical’ (Heilbron, Galileo, 2012). Thus, both Galileo and literature were banned from defending the Copernican Hypothesis, for both would be committing heresy. (Ray, ‘Revolution Western Science,’ 2020). This did little to halt Galileo.
Fourteen years later, in April of 1630, Galileo had just completed his work on the dialogue Concerning the Two Chief World Systems, a piece of literature directly defending heliocentrism (Heilbron, Galileo, 2012). Due to Galileo directly violating the Inquisition’s prior order, he received a request to attend a trial with the Inquisition.
Passage two fits into Galileo’s argument as it is stating what we must first understand in order to grasp the concepts he puts forth to defend the Copernican Hypothesis. In our time, this statement is parallel to taking an introductory course to ensure one has the foundation for more significant concepts to be built off. The passage is saying; we must first understand that the motion of earth will be impossible for us to perceive, as we follow the same movement as the earth. As the earth moves, it moves us in the same pattern of motion. Thus we are blind to this movement as it is all we have ever known.
Furthermore, it is explained that we should not look at motion on earth to tell us how it moves because all objects on earth move with it, similar to us. Instead, one needs to look for objects that move separately from the earth to be able to tell whether any motion can be attributed to the earth. Ideally, these objects are other planets. A more in-depth look at the passage reveals if a movement does not apply to any other planetary body, like the moon, the specific movement can only be attributed to that body; thus, the earth cannot be assumed to have the same movement.
Although the Inquisition’s punishment for Galileo was placing him on house arrest until he passed away, it is the sincere hope that Galileo was able to know in 1992 the Catholic Church stated his view of the Solar System and heliocentrism was indeed correct. At large, the context, meaning of the passage, and the history of Galileo speak to the fact that we often trust what we see or what we are told as real, truthful, and of value; the very fact Plato’s Allegory of the Cave in the passage one reminds us to be wary of.
Rene Descartes wrote this passage in his work ‘Principles of Philosophy.’ More specifically, the passage is from Part 1 of the work. To understand this quote, we must first understand why Descartes thought a new metaphysics was necessary for his physics to be sound and to understand the context of the world he was living in. In the year 1641, Descartes released Meditations on First Philosophy, which created many controversies leading to Descartes acquiring both admirers and enemies (Grosholz, Cartesian Method and the Problem of Reduction, 2011). Due to the controversies, Descartes released his Principles of Philosophy in 1644, which had the goals of explaining the basis of his science described in Meditations on First Philosophy.
The seventeenth century was a time of moving away from religious or mythical explanations of science and towards mathematical and mechanistic explanations (Ray, ‘Revolution Western Science,’ 2020). This movement meant there was an increase in describing the natural world by referring to the motion of matter in mathematical ways. Descartes was not the first to think of mathematical and mechanistic descriptions of the natural world, but his works were of immense significance to the development of it.
Knowing the context in which surrounds the passage, the meaning becomes much more apparent. Descartes’s physics presented in his Principles of Philosophy rests on one claim that is within this passage. When the passage says ‘extension in length, breadth, and depth constitutes the nature of corporeal substance,’ it is stating that the natural world can be explained by the size, shapes, dimensions and positions of things, what we know to be geometry. This is advantageous as unlike prior religious explanations for natural phenomena, which were uncertain, the use of geometry, a type of mathematics, allows for the same certainty in explanations of natural phenomena as one has in mathematics.
Furthermore, instead of including earth, air, fire, and water, like metaphysics do (Ray, ‘Revolution Western Science,’ 2020), the passage explains that there are two substances in the world; mental and physical. Mental substances are those we can think of while physical substances were those that could be explained by geometry. This meant that Descartes believes there is genuinely only one type of substance we can observe; Physical. Therefore, Descartes introduced the concept that all observable natural phenomena could be explained by relying on only a few concepts, which all had their foundations in what we know to be geometry.
This passage fits into Descartes’ argument as it highlights his belief that metaphysical concepts of matter, form and the elements, made viewing the world unnecessarily complicated. Descartes thought that the incorporation of these concepts created a nearly impossible situation for describing only the motion of matter. Descartes created Principles of Philosophy to allow for a new view that is much simpler and more precise than the view metaphysics presented (Bruno & Baker, Math & mathematicians: the history of math discoveries around the world, 2003).
Passage four is from Issac Newton’s Mathematical Principles of Natural Philosophy, better known as Principia. The passage is included in the second edition of Principia and is within the general scholium (‘A Brief Guide to Interpreting Isaac Newton’). Newton used the addition of the general scholium as a supplement that explains details necessary to understand his three laws and the theory of gravitation fully but is not explicitly stated in the first edition of Principia.
In 1684, Robert Hooke, a prominent scientist of the time and later a rival of Newton, conversed with Christopher Wren and Edmund Halley, two astronomers (‘Issac Newton – Key People’). The topic of conversation was Hooke’s principle of inverse squares, which states that ‘any physical quantity is inversely proportional to the square of the distance from the source of the physical quantity’ (‘Inverse Square Law, General’). Later that year, Halley visits Newton, where they also discuss the principle of inverse squares and the relationship it has with planetary orbits, as Halley was an astronomer after all. Halley believed that the principle of inverse squares was at the root of the planetary orbit when Newton tells Halley that he has indeed already calculated it. Halley immediately encourages Newton to publish on the topic and include his calculations. Three years later, in 1687, Principia was published.
Principia stated Newton’s three laws of motion and later stated the theory of gravitation, which Newton was able to provide extensive mathematical proofs for. Passage four is reflecting Newton’s Theory of Gravitation, which made the case that the universe is held all together by a network of gravity. This network pulls on every item in the solar system. In the first line, he still acknowledges the fact that he has not accredited gravity to any processes or causes; he has only endorsed the fact that the solar system is held in orbit by a network of gravity. Furthermore, Newton makes it clear in the passage that he has studied and explained his theory of gravitation in observable and mathematical ways so others cannot easily reject the theory. At the end of this passage, Newton explains that it is not the surface of an object that gravity acts upon, but rather, gravity acts upon the mass and density of an object.