Showing posts with label Timaeus. Show all posts
Showing posts with label Timaeus. Show all posts

Tuesday, January 21, 2014

Æther or...

[I am on a brief vacation, so here is a post from the past. This post first appeared 25 August 2012.]

Speaking of æther...*

In Greek mythology, Æther was the offspring of Erebus (deep shadow) and Nyx (night). Despite springing from dark parents, the word is related to the verb that means "to incinerate";** "æther" was used to refer to pure fresh air, something more pure than ordinary air; in fact, a pure air that was breathed by the gods.

Plato's Timæus (which was very popular for medieval scholars, as I've mentioned before) and his student Aristotle both considered æther crucial to the structure of the universe. Aristotle called it the "fifth element" and described its superiority over earth, air, fire and water because it did not have their limiting properties (hot or cold, wet or dry) and was unchangeable. It was also called quintessence which means "fifth essence/element."

The Greek philosopher Plotinus (c.205-270) taught that there was a supreme "One" that existed prior to all created things, was synonymous with "Good" and "Beauty," and was like a light shining in a void. To the medieval Christian mind, Plotinus was describing God, and therefore was one of those non-Christian philosophers worth listening to. Plotinus said æther was immaterial and could be moved through; he also said there was no such thing as empty space.

Small wonder then that the Middle Ages filled the area above the earthly atmosphere, the space through which the celestial spheres rotated and planets and stars moved, with æther. Æther could not be disproved, and the vacuum of space was as difficult to imagine for the Middle Ages and later as "zero" was for the Romans earlier. The 17th century philosopher Robert Fludd fused Plotinus and Genesis when he explained:
The middle region of the universe, created on the second day, has various names because of the action of the light-stuff as it extended downwards; for, taken by itself, with regard to its own particular material, it is called the Middle Spirit, after the dispersal of darkness: compared to the upper sky, that is, to light-stuff, or mixture of light-stuff and spirit, it is called Ether... [Robert Fludd, The Technical, Physical and Metaphysical History of the Macrocosm and Microcosm, 1617-1624]
The scientific theories were there for all to read and understand.

To be totally honest, the "ether" being tested for in the Michelson-Morley experiment was not conceptually the same æther discussed so extensively in classical and medieval times, but the descent from one to the other clearly runs through the philosophical writings of Western Civilization. Æther was here to stay, until modern technology could eliminate it from our worldview.

*With a nod to Brian Koberlein (on Google +) for shamelessly stealing this idea and his title.
**The name Æthiopia was coined because the inhabitants were black-skinned, as if burnt by the sun.

Wednesday, November 14, 2012

Natural Philosophy

William of Conches (1085-1154), as mentioned yesterday, wrote on Plato's Timaeus. The Timaeus was a popular work or analysis because, for a long time in the Middle Ages, it was the only work of Plato accessible to scholars. Medieval scholars, looking to create a "unified theory" of the world, did not want to reject material from the venerated philosophers of the past—even if they were pagan. Instead, they tried to reconcile earlier writers to Christianity to make a complete picture.

Natural Philosophy—the attempt to explain how the world works—had its own goal of reconciliation: to explain how a world where choice was possible could co-exist with a God who oversaw and was the motivator of everything that happened. There is an idea that science and religion find themselves in conflict because determining physical causes is pointless in a world where God determines everything. The classic example of this is: what should a good Christian do if he becomes ill? Should he visit a priest or a doctor? Is illness a divine punishment for sin, or best understood as a physical failing that can be treated?

In the Middle Ages, of course, the sufferer would not take chances, and would visit both. But men like William of Conches wanted to bring these two sides intellectually into agreement. He recognized that God was the ultimate cause: His omnipotence made him the primary cause that underlies everything in the universe. As a natural philosopher, however, William drew a distinction between this aspect of God and His methods for achieving His aims. There are actions, he said, that are secondary causes.

For instance, if I put a kettle with water on the stove to make tea and turn on the flame, my actions will cause the water to boil. A natural philosopher can examine the boiling water, measure its temperature, gauge the length of time it takes to boil and how active the boiling is, and find uses for boiling water. Those are all secondary causes and effects, however; the primary cause is my desire to make tea and my application of heat. The natural philosopher can learn about heat and water without knowing about my desire for tea. If he observes the water heating several times, he will learn to predict the outcome through his understanding of natural law.

What about miracles? Well, a miracle is an event that we recognize happens that contravenes natural law; in order to recognize a miracle, however, William said we first need to thoroughly understand natural law. By analyzing natural laws, the philosopher does not challenge God's authority; he is analyzing the secondary causes, with the understanding that they are an "additional layer" between God and the world.

Given that miracles are possible, however, does this invalidate our observations of natural law and are reliance on our predictive ability regarding them? For his part, William was very clear: he believed that God was loving and consistent, rather than capricious. The natural laws that God established would remain natural laws forever. The few times we observe something different are either a miracle—an anomaly that we do not have to understand, or merely more information that will enhance our understanding of natural law.

Tuesday, November 13, 2012

The Flat Earth

In 1620, Sir Francis Bacon published Novum Organum ("The New Organon," by which he meant a new interpretation of nature). In it, he claimed that the ancient fathers of the Christian church did not tolerate a belief in a round Earth. It is probably this work that influenced the popular belief ever since that the Middle Ages, or religion, were steadfast in their belief in a flat Earth.

There is plenty of evidence to the contrary, however. True, there was "evidence" in the Middle Ages of a flat Earth. The Mappa Mundi (Map of the World), meant to portray the part of the world believed to be habitable, does make the world look flat and finite. Way back in he 3rd century BCE, however, Eratosthenes had coined the term "geography" and measured the circumference of the clearly round Earth by noting the difference in shadows of a stick at noon on two points many miles apart; the angles and length of the shadows told him that the sun was shining down on the surface at different angles, and the surface was therefore curved.

As revered an early christian as Boethius (480-524, mentioned here) in De consolatione philosophiæ (The Consolation of Philosophy) reminds us of how small we are in the grand scheme of things with this:
It is well known and you have seen it demonstrated by astronomers, that beside the extent of the heavens, the circumference of the earth has the size of a point; that is to say, compared to the magnitude of the celestial sphere, it may be thought of as having no extent at all.
Medieval sources even quote Pliny the Elder's figure of 29,000 miles for the circumference, a remarkably accurate figure.*

So was there a conflict between science and Christianity? Depends who you talk to, I suppose. William of Conches (1085-1154), who may have been a tutor to the young man who became King Henry II of England, wrote extensively on reconciling the origin of the cosmos in Plato's Timaeus with Genesis. The Bible may have described the earth as flat, but William knew this should not be taken literally, explaining:
The authors of Truth are silent on matters of natural philosophy, not because these matters are against the faith, but because they have little to do with the upholding of such faith, which is what those authors were concerned with.
As learning spread—specially with the advent of mass printing—perceptions of the Earth's shape would have spread thanks to re-printed classical works. Columbus' idea to go west to arrive at an eastward point was not a risky gamble or a brilliant insight. Other "facts" in the Bible were also understood to be not literal: Pope Innocent III, for instance, knew that the Moon shone with reflected light, even though the Bible refers to the Sun and Moon as "two lights."

So what account for the learned Bacon's statement? It may have something to do with the conflict between Galileo and the Church. Although the famous trial would not take place until 1633, Galileo had received a formal Admonition in 1616, warning him:
to relinquish altogether the said opinion that the Sun is the center of the world and immovable and that the Earth moves; nor further to hold, teach, or defend it in any way whatsoever, verbally or in writing; otherwise proceedings would be taken against him by the Holy Office; which injunction the said Galileo acquiesced in and promised to obey.  [link]
It is very likely that Bacon and the rest of Europe's scientific community was aware of this growing conflict. In this historical context, Bacon's statement can be seen as a condemnation of the Church because of a recent action—even though for centuries the knowledge of a round Earth was common.

*In fact, the original figure might have been more accurate than we suspect: it was given in Greek stadia, a measurement which meant different things to different users. Our best interpretation is 29,000 miles, but if Pliny were using stadia of a slightly shorter length... .

Friday, June 22, 2012

The Antipodes

As the unknown becomes close and familiar, imagination must seek new realms further away. Modern fiction doesn't write about alien life on the Moon or Mars or Venus, since we now "know" those spheres. In the Middle Ages, it was assumed that fantastical lands and creatures existed "over there." As far lands such as Africa, for instance, began to be explored and found mundane, the fantastical was mentally placed in a more distant spot.

The Antipodes (literally "opposite feet": the place on the globe directly opposite to where you are standing)* fascinated the Middle Ages for both philosophical and geographical reasons. On the one hand, the idea had come to them from the Classical World, and so was difficult to dismiss. This was the place that held creatures out of legend: Cyclopes, dog-headed men, Sciopods whose single large foot could be used as an umbrella when they lay on their backs, Blemmyae with faces on their torsos. On the other hand, the Medieval idea of symmetry demanded that there be lands to the far south, balancing the known lands in the north. Especially as the idea of earth's roundness took shape, Africa wasn't enough to satisfactorily balance Europe and Asia.

The Antipodes were also a natural extension of the theory of "zones." Since it became very cold up north, and hotter as you went south, it was assumed that the temperate zone enjoyed by most of Europe had a counterpart below the equator which was equally inhabitable. Below that, of course would be the area that is opposite the Arctic: the Anti-Arctic, or Antarctic.

The term was first used by Plato in his Timaeus. It was first used in English in 1398 in John of Trevisa's translation of Bartholomaeus Anglicus' De Proprietatibus Rerum (On the Order of Things):
Yonde in Ethiopia ben the Antipodes, men that haue theyr fete ayenst our fete.
(Yonder in Ethiopia are the Antipodes, men that have their fete against our feet.)
Some in the Middle Ages used the image of upside-down men as a reason to reject the Earth as a globe and opt for a flat Earth. Plato had addressed this himself, however, in an assumption of orientation that he does not call gravity but that works the same way:
For if there were any solid body in equipoise at the centre of the universe, there would be nothing to draw it to this extreme rather than to that, for they are all perfectly similar; and if a person were to go round the world in a circle, he would often, when standing at the antipodes of his former position, speak of the same point as above and below; for, as I was saying just now, to speak of the whole which is in the form of a globe as having one part above and another below is not like a sensible man.
But sensible men apparently did not read the Timaeus, or never grasped the concept of "up" and "down" being relative to where you were standing. A universally accepted map of the world was unknown; maps of the world typically took one of four forms, which we will look at tomorrow.

*Have fun finding your antipodal point here.

Thursday, June 7, 2012

Plato Bridges the Big Bang & Genesis

Plato's Timaeus contains a description of the origin of the universe that was much discussed in the Middle Ages. For Plato (or for Socrates, the speaker), all that exists began as a formless chaos, with all elements mixed. Understanding that effects have a cause, he postulates a force he names the Demiurge that acts upon the chaos and gives it shapes that conform to ideal forms that exist in the Demiurge's "mind." He further explains that, for him, each minutest particle of an element had a regular shape. He uses geometric forms:
  • Fire = Tetrahedron
  • Earth = Cube
  • Air = Octahedron
  • Water = Icosahedron
Some have noticed that his description of the origin of the universe seems to anticipate the Big Bang Theory; Mohr and Sattler go into more detail in One Book, The Whole Universe: Plato's Timaeus Today.

The Middle Ages, however, had its own version of the origin of everything to which it compared Plato. St. Ambrose (c.340-397) considered the differences between Plato and Genesis to be Plato's "errors." Ambrose's student, St. Augustine, however, embraces the similarities, specially appreciating Plato's contention that, since the world around us seems pretty good to us, it must be because the Demiurge was determined to make a world that was as good as it could be. The growing field of philosophy found more and more use for Plato in developing a "modern" world view.

Of course not all of Plato was palatable to all later thinkers. Plato tells us that the Demiurge:
  • Made the world into the shape of a globe, the ideal shape to encompass all other forms.
  • Imparted circular movement to the world, as the most uniform and suited to an ideal shape.
  • Created the soul of the world, linking all things on the earth with each other.
But even later ages would learn to appreciate the idea of the Earth as a globe, that it rotates on its axis, and that the Earth is a complex ecosystem of interlocking parts. Not too shabby.