Metaphysics of Materialism
Materialism is not a new theory of metaphysics. It traces its roots back to the early Greek philosophers before Socrates. When Thales deduced that the fundamental substance of everything was water he was, in essence, giving a materialist answer to that question. The same can be said for Empedocles postulating the existence of four elements: air, earth, fire, and water. The atomists, Leucippus and Democritus, proposed the fundamental material substance with which we are somewhat familiar as the building block for all material substances; the atom.
With the rise of Cartesian metaphysics in the 17th century, however, materialism seemed to be on the way out. Descartes proposed that, at least concerning human beings, two radically different substances (mind and matter) interacted. This did not go over so well with at least one of his contemporaries, namely, the English philosopher Thomas Hobbes. Descartes gave Hobbes a copy of the manuscript for the Meditations on First Philosophy and Hobbes came back with several important criticisms centered on the inherent problems with dualist metaphysics.
Hobbes proposed materialism as a solution to the problem of interaction which was at the heart of Descartes' metaphysics. In brief, Hobbes reasoned that everything in the universe was a material substance. The only way something could be a "spirit" (Hobbes' word for the immaterial substance Descartes referred to as the "thinking thing") was to be outside of the universe and there was only one being that fit that description: God.
This version of materialism with God outside the universe went over very well with Isaac Newton whose scientific theory was thoroughly materialist but who kept an open mind about God as the author or creator of the giant mechanistic universe. Newton's universe is often described as a giant clock with God winding it up. Newton's theory is elegant in its simplicity and universality leaving the workings of nature in the hands of three laws of motion.
The elegance of this theory hardly betrays the underlying philosophical problem. If the universe is like a giant machine obeying intractable laws of nature then everything must be a slave to these laws. There can be no exception for human beings since we too are in the universe. So this metaphysical position implies that there is no free will. That is everything is caused "in such a way that it could not be otherwise" (Miller, p. 111). This is the problem of determinism.
Many people found this implausible. After all, if everything is determined, how come we can't predict what will happen? The answer was supplied in part by a gambling epidemic in France during the time of Napoleon. Now, gambling attracts two kinds of people; suckers and mathematicians. It is to the latter that we look for our answer; the French mathematician Pierre Simon de Laplace. He took materialism and determinism to its logical conclusion by saying that if (a big if) we knew everything there was to know about a specific time and place in the universe we could predict with exact accuracy everything else that would happen since everything is determined by previous causes. So how come we can't predict with exact accuracy? Simple, says Laplace, because we don't know everything about a specific time and place in the universe. There are too many variables to account for and our knowledge is always imperfect. But, we can compute with good mathematical accuracy how imperfect our knowledge is and what effect this will have on our accuracy. While this is a useful skill for the gambler it is more important for us the basics of probability.
Ironically, for our story, it was a probability, i.e. the lack of certainty that was to offer a potential solution to the problem of determinism. But before we get to that we need a little background information on the world of materialism in the 20th century.
Newton's theory itself, or at least the part that dealt with gravity, had an important problem. Gravity was supposed to work at a distance through space to keep everything in its proper place; like the moon revolving around the earth. The trouble is space is empty (well it was for Newton). The question then becomes, how can gravity work through space to exert itself on the moon; or anything else for that matter? This is sort of like Aristotle's problem of separation. Interestingly enough, the answer was to come from a borrowed idea of Aristotle: aether.
We needed aether for another reason as well. Around the turn of the 20th century, a scientist named Young discovered that light traveled in waves. This was a problem for Newton as well because the light was supposed to travel instantaneously through space (which was empty, remember?). Well, if light traveled in waves it very definitely took time to travel. And, if they traveled in waves what were the waves in? Young called the something aether. Interestingly enough, aether was also used by Descartes in his theory on gravitation.
Now, all we had to do was find it. Two physicists at the University of Cleveland constructed an experiment to have a go at this. Their names were Michelson and Morley. The experiment they constructed to find the aether failed which left everyone startled. If there was no aether then everything was up for grabs. No aether, no light waves, no place for gravity to work, no anything! This would also be a problem for another gentleman named Marconi who was playing with waves; this time radio waves.
It fell to Albert Einstein, working in the Swiss patent office at the time, to solve the problem. It turns out that we only need aether if another of Newton's postulates is true; namely, that time and space are absolute. According to Einstein, the speed of light cannot be invariant (i.e. constant) while at the same time space and time are absolute. What the speed of light shows us is that the aether doesn't exist which is not a problem if we postulate that time is relative. In other words, if time and space are objective frames of reference then aether is necessary as a reference point for measurement. But if they are not then we don't need aether; which was just fine for Einstein because his theory of relativity implied that time and space are relative to one's frame of reference. So we don't need the aether; just as well since we couldn't find it anyway.
Among its other startling implications, Einstein's theory equated matter and energy and, more relevant for our story, equated gravity and acceleration. As a sidebar, his theory also implied that everything traveled at the same speed: the speed of light! One other important implication of Einstein's theory was the wave-particle duality that led to quantum physics; a theory Einstein himself never felt comfortable with. His disagreement with it led him to say "God does not play dice with the universe." But in experiments, there is always a small probability of making a mistake and it was due to one such mistake by two physicists, Davisson and Germer, which led to the uncertainty that Einstein didn't like.
The problem with Einstein's theory (there's always a problem!) was that it only worked at the big level; gravity and its effects on big things like planets and galaxies. However, it did not work at the subatomic level where electrons move in fairly strange ways. This arena of the universe was the province of quantum mechanics. This theory was the brainchild of, among others, Max Planck, Niels Bohr, and Werner Heisenberg. Heisenberg, in particular, is relevant to our original problem of determinism. His uncertainty principle implied that there was a limit to how much knowledge we could have at the subatomic level.
Simply put the uncertainty principle says that our knowledge of one attribute comes at the expense of knowledge of another attribute. For example, say you want to know how fast an electron is traveling and you'd also like to know where it’s located. Well, you can learn about its velocity but then you won't know where it’s at. Or you can find out where it’s located but then you won't know how fast it’s going. What's worse to measure anything about the little electron (or any other subatomic particle for that matter) you have to see it which means you have to shine a light on it. But the light particles will affect what the electron is doing. So there's no way to tell whether the electron is doing what it's doing naturally or because you're observing it.
Einstein, in particular, didn't like the implications of this. It seemed like quantum theory was saying that the reason we couldn't know was that there was no determined reality there to know until we observed it. For Einstein, this implied that the universe was not orderly. It was all just random. But surely, "God doesn't play dice with the universe." Well, perhaps God does.
It turns out that quantum theory is correct. The reason for the limit to our knowledge is not due to the inadequacy of our measuring ability rather it is that at the subatomic level there is a fundamental indeterminism. The fabric of the cosmos is what physicists call "probability waves." In a sense things don't exist (at least at the subatomic level) until their probability wave collapses; that is until we observe them and in doing so make them actual. As we'll see in another chapter, the philosophical roots of this are in 18th-century idealism.
About the problem of determinism, the question then becomes: If there is a fundamental indeterminism at the subatomic level, couldn't it be possible that there is a level of indeterminism at the macroscopic level? In other words, if there is no "observable causal determinism at the level of atomic and subatomic particles" then there may be no causal determinism at all! (Miller, p. 116) So our worries are over!
Except for one major problem; as opposed to the somewhat minor problems we have already considered! Einstein's theory of relativity is well tested and confirmed for the level of large objects and gravity. Quantum physics is well tested and confirmed for the level of very small objects. However, the two theories are fundamentally incompatible which leads many scientists to speculate that there's more to the story. It seems intuitively implausible that the fundamental laws of nature would be fundamentally incompatible with one another. Einstein himself postulated that what would need to be found was a theory to unify these two incomplete theories. He called it a unified field theory. These days, scientists call it the grand unification theory and the search is ongoing.
The latest attempt to construct such a G.U.T. is string theory. The most prominent advocate for this is Brian Greene who several years ago authored a book titled The Elegant Universe where he outlines the problem which leads to the search for a unified theory and string theory's attempt to do this. The details are complicated, but, simply put, the idea is that the fundamental particles we are familiar with, the electron, the quarks (there are several varieties of these including the charm quark and the strange quark), and the force particles (like the gluon, weak gauge boson, and photon), are all in reality composed of a more fundamental substance. Think of this as a very tiny filament of matter shaped like a rubber band that vibrates. This is called a string. Some of the strings are closed loops while others are simply strands. Each one vibrates at a different frequency and depending on that frequency the string will be either an electron, a quark, or whatever.
Among its more radical implications, string theory postulates that reality is composed of ten or eleven dimensions. We are now familiar with four dimensions; three space dimensions and a one-time dimension. As we'll see, even these seemingly simple concepts have deep philosophical implications. Are space and time real or just abstract concepts we use as a shorthand description of reality? Einstein proposed, and we now have good evidence for the fact, that space and time are intimately connected and form what Greene calls the "fabric of the cosmos." The consequences of this link are quite amazing. “If you look up into the night sky you can see many stars. The light from each of those stars takes time to travel. So you're seeing the stars as they were in the past. The farther away the stars are the further back in time you're looking. Say you look at a star that's 6000 light-years away. You're seeing the light from that star as it was 6000 years ago (that's how long it’s taken to get to your eyes). Imagine someone on a planet orbiting that star looking at us. They would be seeing us as we were 6000 years ago. Which of those two is now?”1
1. This quote was taken from an Alan Parsons Project song titled “Temporalia” on the CD The Time Machine.
With the rise of Cartesian metaphysics in the 17th century, however, materialism seemed to be on the way out. Descartes proposed that, at least concerning human beings, two radically different substances (mind and matter) interacted. This did not go over so well with at least one of his contemporaries, namely, the English philosopher Thomas Hobbes. Descartes gave Hobbes a copy of the manuscript for the Meditations on First Philosophy and Hobbes came back with several important criticisms centered on the inherent problems with dualist metaphysics.
Hobbes proposed materialism as a solution to the problem of interaction which was at the heart of Descartes' metaphysics. In brief, Hobbes reasoned that everything in the universe was a material substance. The only way something could be a "spirit" (Hobbes' word for the immaterial substance Descartes referred to as the "thinking thing") was to be outside of the universe and there was only one being that fit that description: God.
This version of materialism with God outside the universe went over very well with Isaac Newton whose scientific theory was thoroughly materialist but who kept an open mind about God as the author or creator of the giant mechanistic universe. Newton's universe is often described as a giant clock with God winding it up. Newton's theory is elegant in its simplicity and universality leaving the workings of nature in the hands of three laws of motion.
The elegance of this theory hardly betrays the underlying philosophical problem. If the universe is like a giant machine obeying intractable laws of nature then everything must be a slave to these laws. There can be no exception for human beings since we too are in the universe. So this metaphysical position implies that there is no free will. That is everything is caused "in such a way that it could not be otherwise" (Miller, p. 111). This is the problem of determinism.
Many people found this implausible. After all, if everything is determined, how come we can't predict what will happen? The answer was supplied in part by a gambling epidemic in France during the time of Napoleon. Now, gambling attracts two kinds of people; suckers and mathematicians. It is to the latter that we look for our answer; the French mathematician Pierre Simon de Laplace. He took materialism and determinism to its logical conclusion by saying that if (a big if) we knew everything there was to know about a specific time and place in the universe we could predict with exact accuracy everything else that would happen since everything is determined by previous causes. So how come we can't predict with exact accuracy? Simple, says Laplace, because we don't know everything about a specific time and place in the universe. There are too many variables to account for and our knowledge is always imperfect. But, we can compute with good mathematical accuracy how imperfect our knowledge is and what effect this will have on our accuracy. While this is a useful skill for the gambler it is more important for us the basics of probability.
Ironically, for our story, it was a probability, i.e. the lack of certainty that was to offer a potential solution to the problem of determinism. But before we get to that we need a little background information on the world of materialism in the 20th century.
Newton's theory itself, or at least the part that dealt with gravity, had an important problem. Gravity was supposed to work at a distance through space to keep everything in its proper place; like the moon revolving around the earth. The trouble is space is empty (well it was for Newton). The question then becomes, how can gravity work through space to exert itself on the moon; or anything else for that matter? This is sort of like Aristotle's problem of separation. Interestingly enough, the answer was to come from a borrowed idea of Aristotle: aether.
We needed aether for another reason as well. Around the turn of the 20th century, a scientist named Young discovered that light traveled in waves. This was a problem for Newton as well because the light was supposed to travel instantaneously through space (which was empty, remember?). Well, if light traveled in waves it very definitely took time to travel. And, if they traveled in waves what were the waves in? Young called the something aether. Interestingly enough, aether was also used by Descartes in his theory on gravitation.
Now, all we had to do was find it. Two physicists at the University of Cleveland constructed an experiment to have a go at this. Their names were Michelson and Morley. The experiment they constructed to find the aether failed which left everyone startled. If there was no aether then everything was up for grabs. No aether, no light waves, no place for gravity to work, no anything! This would also be a problem for another gentleman named Marconi who was playing with waves; this time radio waves.
It fell to Albert Einstein, working in the Swiss patent office at the time, to solve the problem. It turns out that we only need aether if another of Newton's postulates is true; namely, that time and space are absolute. According to Einstein, the speed of light cannot be invariant (i.e. constant) while at the same time space and time are absolute. What the speed of light shows us is that the aether doesn't exist which is not a problem if we postulate that time is relative. In other words, if time and space are objective frames of reference then aether is necessary as a reference point for measurement. But if they are not then we don't need aether; which was just fine for Einstein because his theory of relativity implied that time and space are relative to one's frame of reference. So we don't need the aether; just as well since we couldn't find it anyway.
Among its other startling implications, Einstein's theory equated matter and energy and, more relevant for our story, equated gravity and acceleration. As a sidebar, his theory also implied that everything traveled at the same speed: the speed of light! One other important implication of Einstein's theory was the wave-particle duality that led to quantum physics; a theory Einstein himself never felt comfortable with. His disagreement with it led him to say "God does not play dice with the universe." But in experiments, there is always a small probability of making a mistake and it was due to one such mistake by two physicists, Davisson and Germer, which led to the uncertainty that Einstein didn't like.
The problem with Einstein's theory (there's always a problem!) was that it only worked at the big level; gravity and its effects on big things like planets and galaxies. However, it did not work at the subatomic level where electrons move in fairly strange ways. This arena of the universe was the province of quantum mechanics. This theory was the brainchild of, among others, Max Planck, Niels Bohr, and Werner Heisenberg. Heisenberg, in particular, is relevant to our original problem of determinism. His uncertainty principle implied that there was a limit to how much knowledge we could have at the subatomic level.
Simply put the uncertainty principle says that our knowledge of one attribute comes at the expense of knowledge of another attribute. For example, say you want to know how fast an electron is traveling and you'd also like to know where it’s located. Well, you can learn about its velocity but then you won't know where it’s at. Or you can find out where it’s located but then you won't know how fast it’s going. What's worse to measure anything about the little electron (or any other subatomic particle for that matter) you have to see it which means you have to shine a light on it. But the light particles will affect what the electron is doing. So there's no way to tell whether the electron is doing what it's doing naturally or because you're observing it.
Einstein, in particular, didn't like the implications of this. It seemed like quantum theory was saying that the reason we couldn't know was that there was no determined reality there to know until we observed it. For Einstein, this implied that the universe was not orderly. It was all just random. But surely, "God doesn't play dice with the universe." Well, perhaps God does.
It turns out that quantum theory is correct. The reason for the limit to our knowledge is not due to the inadequacy of our measuring ability rather it is that at the subatomic level there is a fundamental indeterminism. The fabric of the cosmos is what physicists call "probability waves." In a sense things don't exist (at least at the subatomic level) until their probability wave collapses; that is until we observe them and in doing so make them actual. As we'll see in another chapter, the philosophical roots of this are in 18th-century idealism.
About the problem of determinism, the question then becomes: If there is a fundamental indeterminism at the subatomic level, couldn't it be possible that there is a level of indeterminism at the macroscopic level? In other words, if there is no "observable causal determinism at the level of atomic and subatomic particles" then there may be no causal determinism at all! (Miller, p. 116) So our worries are over!
Except for one major problem; as opposed to the somewhat minor problems we have already considered! Einstein's theory of relativity is well tested and confirmed for the level of large objects and gravity. Quantum physics is well tested and confirmed for the level of very small objects. However, the two theories are fundamentally incompatible which leads many scientists to speculate that there's more to the story. It seems intuitively implausible that the fundamental laws of nature would be fundamentally incompatible with one another. Einstein himself postulated that what would need to be found was a theory to unify these two incomplete theories. He called it a unified field theory. These days, scientists call it the grand unification theory and the search is ongoing.
The latest attempt to construct such a G.U.T. is string theory. The most prominent advocate for this is Brian Greene who several years ago authored a book titled The Elegant Universe where he outlines the problem which leads to the search for a unified theory and string theory's attempt to do this. The details are complicated, but, simply put, the idea is that the fundamental particles we are familiar with, the electron, the quarks (there are several varieties of these including the charm quark and the strange quark), and the force particles (like the gluon, weak gauge boson, and photon), are all in reality composed of a more fundamental substance. Think of this as a very tiny filament of matter shaped like a rubber band that vibrates. This is called a string. Some of the strings are closed loops while others are simply strands. Each one vibrates at a different frequency and depending on that frequency the string will be either an electron, a quark, or whatever.
Among its more radical implications, string theory postulates that reality is composed of ten or eleven dimensions. We are now familiar with four dimensions; three space dimensions and a one-time dimension. As we'll see, even these seemingly simple concepts have deep philosophical implications. Are space and time real or just abstract concepts we use as a shorthand description of reality? Einstein proposed, and we now have good evidence for the fact, that space and time are intimately connected and form what Greene calls the "fabric of the cosmos." The consequences of this link are quite amazing. “If you look up into the night sky you can see many stars. The light from each of those stars takes time to travel. So you're seeing the stars as they were in the past. The farther away the stars are the further back in time you're looking. Say you look at a star that's 6000 light-years away. You're seeing the light from that star as it was 6000 years ago (that's how long it’s taken to get to your eyes). Imagine someone on a planet orbiting that star looking at us. They would be seeing us as we were 6000 years ago. Which of those two is now?”1
1. This quote was taken from an Alan Parsons Project song titled “Temporalia” on the CD The Time Machine.