While this is a natural response, I should point out that even though scientists talk of cause and effect, the concept of causation itself is a philosophical one. What it means to say that some event caused another event has to be determined before the scientist can employ the term “cause” in any theory; for the meaning of “cause” is not understood as the result of experimental data or any amount of measuring. Rather, since experiments and measurements are means of identifying or understanding the causes of specific phenomena, the term itself must be understood before we can make any measurements or experiments.
How, then, has philosophical analysis helped us understand what the term “cause” means? This very question was addressed by both the Scottish philosopher David Hume and the German philosopher Gottfried Leibniz. Indeed, their attempts to analyze the concepts of “causation” and “force” led them to conclude that we cannot possibly possess scientific knowledge of these concepts. The reasons why will take us to the heart of why the Force in Star Wars so thoroughly captivates our imagination; we seem to recognize causes even if we have no way of explaining how they work. But in order to see how we arrive at this startling conclusion, we must begin by looking at what we think causes are and why the Force is a cause.
“Size Matters Not”
The Force is a special power that allows the Jedi to act on parts of the world without being in physical contact with those objects. It allows them to move rocks, spaceships, lightsabers, and droids, apparently by using only the mind. And unlike physical and mechanical forces in our world, the size of the objects moved doesn’t matter; as Yoda puts it, “Size matters not.” These objects, we suppose, wouldn’t behave that way without the Jedi being there and willing them to behave that way. So the Force is part of the cause of these events. But the question remains, “What is a cause?”
When we think of a cause, we usually think of an object or event that produces some kind of change; the cause of Alderaan’s destruction is the Death Star. But causes also explain non-changing states as well; we speak of the cause of one’s health or the cause of the world’s existence. So causes are part of our explanations for why things are the way they are, and why things undergo the changes they do. But what makes some event a case of causation rather than mere chance? There has to be some set of conditions that must be met in order to be a true cause. Here’s where David Hume comes in.
David Hume (1711-1776)97 points out that a true cause has three features: temporal priority—the cause comes before the effect; contact—the cause must be in physical contact with what it effects; and there must be a necessary connection between the cause and effect—some law-like connection or reason why the event we call “the cause” must always produce the event we call “the effect.”
A necessary connection between cause and effect is the kind of connection that would not only rule out coincidence, but would show why the effect must be the result of the cause; so that if we knew everything about the cause, we could deduce with perfect accuracy exactly what the effect would be. For example, if the motion in the cue-ball is the cause of the motion in the two-ball that it hits, then there must be a necessary connection between the motion of the cue-ball and the resulting motion in the two-ball. So if we knew what that necessary connection was, then we could tell long before it happened exactly how and why the cue-ball would affect the two-ball, even if we’d never seen any billiard balls collide before. If there were a necessary connection between Luke’s willing for his lightsaber in the ice cave on Hoth and the motion of the lightsaber to his hand, then, if we had a knowledge of that connection, we would know (prior to seeing it happen) how and why the lightsaber would fly to his hand. Necessary connections are part of the explanations of how and why causes produce their effects.
Hume then asks, “What observations do we have of necessary connections between events?” None. According to Hume, we have no knowledge of causes and effects because we have no knowledge of the most important ingredient: the necessary connection between them.
What we observe when we see, for example, a moving cue-ball approaching a stationary billiard ball, is the motion of the cue-ball, followed by contact between the balls, and then the motion in the second ball. But no matter how closely or frequently we examine these events, we’ll never observe the necessary connection between them. We never observe that feature of their interaction that makes it so that the second ball must move when contacted by the moving cue-ball—it’s entirely possible that the second ball won’t move at all after the collision.
The lack of knowledge of any necessary connections means that, no matter how many times we observe the same thing, we can still imagine the second ball not moving after the collision. As Hume puts it, “From the mere repetition of any past impression, even to infinity, there will never arise any new original idea, such as that of a necessary connexion.”98 All we observe is that one kind of event is constantly followed by another kind of event; and so we develop a habit of expecting some kinds of events from the observation of others. Yet there’s no absurdity or impossibility in the typical effect not occurring when the familiar cause does. (Quantum physics tell us that the same causal conditions can have different effects at different times.)
Since, according to Hume, we never observe the necessary connection between cause and effect, we have no knowledge of causation, just a habit of expecting certain kinds of events to be followed by other kinds of events. Causation is thus a mysterious concept. After all, how does the mass of the earth cause the moon to stay in orbit, or cause earthly objects to fall? How does a magnet attract iron to it? Describing the causal mechanism in these kinds of interactions as a force fails to explain how that force does what it does. And in these cases, not only is the necessary connection unobserved, but contact between the objects appears to be missing too!
No matter how many times we see Jedi toppling legions of battle droids with the flick of their hands, we’ll never observe the necessary connection between the motion in the Jedi’s hands and the toppling of the battle droids. We’ll only observe that the one kind of event is followed by the other. But this doesn’t show us that they are necessarily connected. After all, experience tells us that hand-flicking and the toppling of objects at a distance is not typical!
The Force in Star Wars violates our expectations because it too operates in ways quite mysterious to us. It’s by the use of the Force that Luke draws his out-of-reach lightsaber to his hand in the wampa’s ice cave on Hoth. This kind of attractive force is just as mystifying to us as some of the causation we regularly experience, like gravity. So why can’t we lift a spacecraft from a swamp with our minds alone? What prevents that in our universe?
The Power that Keeps On Giving
We learned from Hume that no observation can amount to observation of a true cause. All we have is the habit of expecting things to behave in a certain way. But what if we decided that Hume is wrong? What if we said that “the reason causes produce their effects in the case of the billiard balls is that the cue-ball transfers its motion to the ball it hits”? The problem with this, however, is that, as Gottfried Leibniz (1646-1716) shows us, this concept of transferring motion is just as problematic as the alleged necessary connection. Leibniz, one of the inventors of calculus and a contributor to the scientific revolution of the seventeenth century, argued that the concept of causation between distinct substances is incoherent.
Since Aristotle, one of the fundamental philosophical and scientific concepts has been “substance.” To be a substance is to be a thing with properties. For example, we might describe Yoda as a substance because he is a thing that has properties, such as being old and green, and a thing that moves, talks, is conscious, has a body, and is capable of moral reasoning. These properties depend on the existence of a thing which has them. If the substance of Yoda were annihilated, then there would be nothing to have these “Yoda” properties; there must be something to be old, green, in motion, conscious, and so on. So substances are things
that have properties, and properties depend on substances for their existence.
According to Leibniz, the concept of causation includes the transfer of motion or other properties from one substance (a cue-ball) to another substance (a two-ball). This means that causation is a kind of giving. So, in addition to the concept of substance, we need the further concept of causation as giving. We often think of a cause as an object giving its own properties to another object—the particles in a lightsaber give some of their motion to the particles of metal in a blast-door causing it to heat up. It follows then that causes must have the properties they give to their effects; a lightsaber cannot cause a blast-door to be hot unless it has heat itself.
Now, as Leibniz argues in his Monadology, one body cannot cause a change in another:There is also no way of explaining how a [substance] can be altered or changed internally by some other creature . . . [Properties] cannot be detached, nor can they go about outside of substances . . . Thus, neither substance nor [properties] can enter a [substance] from without. 99
If one physical object, say a cue-ball, were to have a property, say motion, and if that cue-ball were to cause motion in a (presently) stationary eight-ball, then the cue-ball would have to transfer some of its motion to the eight-ball. But how does one substance transfer one of its own properties to another substance? As we’ve said, since properties are properties of something—they’re not free-floating, but attached to substances—then the property of motion can’t be given from the cue-ball to the eight-ball without some part of the cue-ball’s substance moving from the cue-ball to the eight-ball as well. But this doesn’t happen; bodies don’t cause motion in other bodies by giving up part of themselves. When Luke causes C-3PO to rise in the air, he doesn’t transfer any of his own substance to C-3PO’s chair. So causation as the giving of properties from one body to another, Leibniz argues, can’t happen.
The Force, however, is not this kind of causation. When a Jedi knocks over a line of battle droids, he doesn’t transfer some of his motion to the droids. And certainly we don’t think that all causation includes the transfer of properties in this way. What’s being given to the glass by the diamond that cuts it? What property of the earth is given to the falling body? But if we reject this model of causation, then we’re stuck with the problem of figuring out exactly what all instances of causation have in common, by virtue of which they are causes.
“There’s [Not] One All-Powerful Force Controlling Everything”
If Hume is right, we have no knowledge of causation because we lack any observations of the main component of causes: the necessary connection between the cause and the effect. And if the account of causation he examines is correct, which requires that causes be limited to bodies in contact with each other, then things like gravity and electromagnetic force don’t obviously count as causes. On the other hand, if Leibniz is right, the problem is how we account for causes in a way other than substances transferring properties. So the concept of causation is in deep trouble; there seems to be no way to clearly understand how an alleged cause produces its alleged effect.
This conclusion, however, seems to be too much to swallow. Most of us believe that there’s a difference between a true cause and effect and a mere coincidence. But what’s that difference? One likely candidate would be natural laws. One of the features we tend to include in our concept of cause, which seems to help us exclude explanations like coincidence, is law-guided uniformity . The principle of uniformity says that similar causes produce similar effects. A better way to put it is that changes or interactions between objects are governed by general laws so that every time an event of a certain type occurs, the laws dictate that effects of a certain type will follow.
So, in the Star Wars universe, the laws could be such that every time a Jedi desires to draw his lightsaber to his hand from across the room, the Force makes it happen. Of course, this doesn’t solve the problem because it doesn’t tell us why it happens, or what makes this law able to produce these kinds of interactions; only that in this kind of universe the laws make it happen. If one of the lessons we learned through Hume and Leibniz is that explaining how causes do their work is too difficult, then maybe we ought to think of causes and their effects as somehow correlated (we assume that the two events are related to each other, for example, whenever Darth Vader gets frustrated, another admiral bites the dust) in what seems to be a law-governed way and give up trying to figure out whether or how they are necessarily connected.
There are, however, two features of this suggestion that we ought to notice. First, the fact that we describe these causal interactions as law-governed presupposes that there’s some natural connection between certain events, so that whenever an event of one kind occurs, it’ll be followed by an event of another kind. And secondly, even if we thought that causes and effects were merely probabilistically related, so that whenever some kinds of events occur, then it’s likely that an event of a certain kind will follow, that still would presuppose that there’s a natural and law-governed connection between the events; otherwise, we wouldn’t have a reason to think of these events as causally related. But what evidence could we have of such a law-governed connection?
The obvious answer is that we have the evidence of a long train of past observations. Whenever Darth Vader exerts pressure on the throats of people, as many Imperial officers have discovered, they choke. And this happens every time Vader exerts pressure on their throats. So the cause of the choking is the pressure on the throat. So, we may infer, that next time Vader exerts pressure on someone’s throat, it will cause them to choke too. This appears to be a reasonable inference based on experience, and one that incompetent Imperial officers ought to keep in mind!
And if there are such law-governed connections, they would allow us to make accurate predictions based on past evidence. So the earmarks of a natural causal law include observations that whenever events of a certain type (Darth Vader willing the asphyxiation of an Imperial officer) occur, they’re followed by events of a certain type (the choking of the officer), and these observations will typically allow us to make accurate predictions of similar events employing the described conditions. Hume, however, argues that this kind of argument is deeply flawed. We can’t generalize from past experience that there’s a law-governed connection between events unless we use circular reasoning—that is, we assume the truth of what we want to prove in order to prove it.
Laws of nature are general descriptions of how all matter behaves all over the universe whether we observe it or not. But how are such laws ever justifiable? How are we to justify a claim about how all matter must behave all over the universe at all times? We can’t—at least not by observation. So is there an argument to show that there are laws of nature?
Well, we might argue that since the suns of Tatooine have always risen and set in the same way everyday, and they seem to be behaving in their typical way now, it’s reasonable to infer that they will continue to do so in the future because there is a law of nature guiding their motion. But, Hume points out, this argument only works if we have reasons for thinking that past regularity is evidence of future regularity. There are lots of things that were true in the past, and are true now, but will not be in the future; that’s why people buy insurance. In The Empire Strikes Back, it might have been true to say that Darth Vader had always obeyed the Emperor, and is now obeying the Emperor. But can we infer that he will always obey the Emperor in the future? Not unless tossing him down the second Death Star’s reactor shaft counts as obedience! 100
The only way to justify our belief that the future will resemble the past, such that things that were true in the past will remain true in the future, is if we had reasons for thinking that nature is orderly. But nature is orderly only if there are laws of nature. That is, past regularity is only evidence of future regularity if there are laws of nature, but this is what the conclusion of the argument is supposed to establish. This argument would be circular because we can’t assume that t
here are laws of nature in order to prove that there are laws of nature! So, Hume concludes, there is no non-circular argument which shows us that there are laws of nature.
Failing to specify how causes and effects are correlated allows things like coincidence, magic, wishful thinking, and the Force to count as true causes. But that’s not something we can tolerate as a scientific society. It’s precisely the account of how the laws regulate events that distinguishes true causes from non-causes. But if we can’t legitimately establish that there are laws of nature, then we’re in no position to claim that these laws explain what is required to be true causes. So laws of nature can’t ground our distinction between true causes and non-causes.
In sum, while we deeply believe that there are differences between real causes and pseudo-causes, precisely articulating and justifying those differences has eluded us. What this leaves us with is experiment and probability. In our search for an account of specific cause and effect relationships we must experiment to provide reasons for thinking that the correlations we observe between specific kinds of events isn’t merely coincidental. And while we may never be absolutely certain about the truth of our conclusions, we need not embrace Han Solo’s famous words: “it’s all a lot of simple tricks and nonsense.”
“May The Force Be with You”
This discussion doesn’t show that there are no causes or laws of nature, nor does it show that inquiry into the meaning of “causation” is fruitless. But it does seem to show that our thinking about causation isn’t yet precise enough to do the kind of work we’d like it to. Indeed, our term “cause” probably doesn’t pick out any single kind of interaction, but rather refers to a whole host of different kinds of interactions. Moreover, like causation, the Force remains a deeply mysterious concept to us; neither one is easy to define and explain, but we have no trouble recognizing them. And what’s more disconcerting is that, from how we use the term, the Force qualifies as a kind of cause, even though we remain deeply puzzled by how the Force does what it does!
Star Wars and Philosophy Page 16