Determinism

Since time immemorial mankind has pondered the concepts of fate and free will. Greek myths depict characters who tragically meet their destiny while trying to avoid it. While the logical mind will not yield belief in such mythic fables, a similar concept called determinism seems to be supported by the laws of logic. Determinism is the idea that because of causality only one version of any given event at any given time could possibly exist. In other words an event can happen only in one specific way because the events that caused it happened in a specific way, because the events that caused that happened in a specific way, and so on. If there are unbreakable laws of nature and if the laws of causality are a part of these laws of nature, then the theory of determinism must be true.

This theory may initially seem scary. If everything must happen in a specific way, then in a sense all people are merely puppets, tugged on by invisible strings of causation. If this is the case, then we aren’t driving to work because we ‘want’ to, we must do it because a listless number of reasons we are barely aware of are making us do it. The nature of free will has been debated by scholars, religious figures and philosophers for millennia. While the theories of determinism and free will seem as if they should not work together, a school of thought, compatibilism, seeks to reconcile the discordance between the two seemingly conflicting ideas.

Free will is a hard idea to grasp mostly because it is so hard to define. St. Augustine defines free will as the moral capacity to choose between acts of good and acts of evil (Murray, 2004). If this is the definition that is to be upheld, then determinism must be untrue; a person can make only the good or the evil choice because of prior causes. A compatibilist, on the other hand, might define free will as the “…the unencumbered ability of an agent to do what she wants” (Compatibilism, 2004). This definition does not outwardly seem too different from that of St. Augustine’s, but is much more compatible alongside the laws of determinism. Whereas St. Augustine’s definition implies that two alternate futures exist depending on what moral route said person chose, the compatibilist’s definition implies only that a person will make the choice that suits him or her best. This definition works within the laws of determinism because said choice remains causally determined.

Even so, many may argue that if a choice is causally determined then no choice is being made at all. To them the idea that someone has made a decision is only an illusion; the act of deciding was definitely going to happen and the result of the decision was set by the preliminary causes. This may be true; however, we have no way of solidly knowing why we make the ‘choices’ we do. Consider the following. A thirsty man opens his refrigerator and comes across two beverages: beer and orange juice. One who believes in free will gives the ultimate choice of what beverage to take to the deciding agent, the thirsty man. He will choose either one (or perhaps both or neither) based on his own capacity to decide which choice suits him best at the moment. One who believes in determinism says that he must take out a certain beverage (or both or neither) because of a near infinite list of causes. The compatibilist agrees with both. Though said person ultimately can make only one decision based on deterministic laws, these causes result in said person making the decision of what he wants.

Advocates of free will generally accept one of two descriptions, the ‘Garden of Forking Paths’ model or the ‘Source’ model (Compatibilism, 2004). The Garden of Forking Paths model states that at any given event in which a decision is made, the deciding agent is changing the future. Thus when our thirsty man comes upon his refrigerator and ponders which beverage he will take, at that moment two alternate futures exist; one in which he selects the beer and another in which he selects the orange juice. Of course this is in opposition to the determinist assumption that our thirsty drinker is only able to choose one beverage that has been predetermined by whatever infinite causes bring him to want either beverage in the first place. If free will exists and this is an accurate description, then determinism must be false.

The Source model of free will is different in that it does not necessarily suggest that there are alternate futures. This model describes free will as occurring when a person is consciously the source of an event. With this description our thirsty man exercises his free will simply by actively deciding that he is going to get out of his chair in search of a beverage. This model of free will is not outright at odds with determinism as there is no assertion that there are alternate futures based on one’s choices, only that a person does indeed make choices. Though this initially does not seem to break compatibilist thinking, it can be logically rebutted. The Stanford Encyclopedia of Philosophy, an online encyclopedia maintained by Stanford University, gives this logical argument regarding the failures of the Source model to be compatible with determinism: “A person acts of her own free will only if she is its ultimate source. If determinism is true, no one is the ultimate source of her actions [her actions are caused by other events]. Therefore, if determinism is true, no one acts of her own free will.” If our actions are caused by events beyond our control or awareness then we are not the ultimate source, just an additional part in causal mechanics.

Though free will can be refuted by the laws of determinism and determinism can be refuted by the laws of free will, compatibilists have managed to create ways in which both models of free will can be true under the laws of determinism. The compatibilist who agrees with the Garden of Forking Paths model holds to the deterministic law that nothing can happen which does not happen. Thus when our thirsty man leaves his kitchen with a beer, there is no possibility that he would leave the room with orange juice. Though this person had the option of selecting the juice, he ultimately decided on taking the beer. Though there is a ‘forking path’ implied, only one path is truly viable as, in the end, this person can ultimately only do the thing that he actually did, in this case deciding upon only the one beverage.

Compatibilists who accept the Source description find it difficult to argue the incompatibilist point that people are not the ‘ultimate’ source of their actions. Determinism demands that every event has a precedent cause, thus denying people the ability to be the initial cause of any string of events. To make it more clear, the person who is causing the event to take place is not the ultimate source because something is causing him to make that event occur. This is an acceptable premise; if you yourself have a reason for doing something, then obviously the cause does not spring purely from your will. In order to reconcile the Source model with determinism compatibilists argue the premise that one does not have to be the ultimate source of an event to be exercising their free will. Although our thirsty drinker went to his refrigerator because he was thirsty and he chose the beer because he did not feel like breaking his 9 o’clock drinking habit, to a determinist he still exercised his free will by being a conscious agent in his actions.

The problem with arguing for or against free will is that it is so hard to define and it is only shakily supported itself. Free will assumes that humans and other conscious entities have the ability to make choices, but even these choices have deterministic traits. We generally have reasons for making the conscious choices we make. Our thirsty drinker did not simply get out of his chair and go to his refrigerator for the sake of doing it. A reason is implied, and in this case the word ‘reason’ can be interchangeable with the word ‘cause.’ When he comes across the beverages his decision is going to be influenced by a lifetime of experience as well as concurrent local conditions. Even if the only available explanation for choosing one beverage over the other is that he felt like it, surely this feeling stems from any number of unconscious influences. The deterministic mind might identify these influences as causes. If even that explanation fails and there is no real reason for him having chose one over the other, then it would appear that his having taken one beverage over the other was pure chance. If this is the case then free will is not being exercised, it falls entirely upon mathematical probability. In this model, neither free will nor determinism is true; the universe and the events that make it the way it is are truly random.

This concept of randomness is one of the main arguments used to refute the existence of determinism. Though classical mechanics of physics do imply that given all of the individual forces applied upon a body in motion, its exact trajectory and destination can be calculated without error, there are certain mathematical problems that seem to break down deterministic law by adding an apparently random component. One example of this is the collision of three points with identical properties colliding together at 120 degree angles at the same time (see diagram right). If you use Newtonian physics, then it is impossible to tell what direction these ‘points’ will travel in after the collision. According to the Stanford Encyclopedia of Philosophy, “That they bounce back along their approach trajectories is possible; but it is equally possible for them to bounce in other directions (again with 120 degree angles between their paths)…” If there are tiny physical particles that can be described as points rather than spheres or some other geometrical figure, then should such an event occur determinism, at least as expressed mathematically, would not be able to account for the result of said collision.

Though Newtonian physics and classical mechanics generally uphold deterministic laws, subatomic particles do not follow these laws of motion. In order to make sense of the physics of atoms and subatomic particles, quantum mechanics must be used. Taking quantum mechanics and the General Relativity theory, additional puzzling events seem to dispute deterministic laws. Many of these events are built around black holes, which have two defining parts: the singularity and the event horizon. The singularity is the unimaginably dense center of a black hole and the event horizon is the boundary in which nothing that enters can ever escape. Though there is indication that within the event horizon deterministic law could break down, the objects inside can never escape, thus potentially upholding determinism for the rest of the universe (Causal Determinism, 2010). A third, inner boundary called the Cauchy horizon is another point of contention. This boundary is difficult to describe. Think of light, which travels at the speed of time. Light always travels in a straight line through space; however there are forces within space, such as gravity, that curves space itself. At this boundary the gravity has become so great that light would travel in a perfect circle. Basically this boundary is where objects can no longer be related by cause and effect in any sense, because cause and effect are happening in the same moment of time (Dafermos, 2003, pp. 875-928).

The science of quantum mechanics also notes a failure for many events to be described as occurring causally at all. For example, the decay of a radioactive atom cannot be described causally using the current means we have to observe them, only probabilistically. In other words it is impossible to say for sure when a radioactive atom will break down, only the likeliness that it has or has not broken down over a given amount of time. If this event does indeed happen without having a specific, time-bound cause then determinism would break along the lines of this commonly occurring event alone. The problem is that there are many events like this (far too technical for my understanding) that also appear to occur only probabilistically.

This tendency towards randomness is considered a failure of the field by determinist scientists. Most believe that either a supplemental theory must be added or that the theory must be altered to accurately describe these ‘probabilistic’ events. Albert Einstein himself believed in a ‘hidden variable theory’ stating that there were forces not yet recognized by mankind that caused seemingly random events to occur. This idea was ‘disproven’ until the 1950’s when a scientist named David Bohm designed an interpretation of quantum mechanics that did work deterministically (Causal Determinism, 2010). Since that time more valid arguments have been made that deny causality to these events, and even now nothing has been presented that solidly proves or disproves that these systems work deterministically.

The biggest problem with trying to build absolutes out of the ‘laws’ and theories of science, is that these laws and theories are not truly absolute themselves. Science is ever-evolving and constantly shows that the things that we think we know are wrong. In fact it would not be wholly inaccurate to say that science is technically built on lies; that said if the prior statement were true then it would also be accurate to say that everything we know is a lie. In the end, the problem of whether the world works deterministically or otherwise is not a scientific problem, it is a philosophical one. Wherever you look, science has holes, sometimes small, sometimes gaping. Regardless, until we have devised systems that describe the nature of the world without error and without the possibility for alternate explanation, then we can never know for certain whether the way we believe the world to work does in fact work that way. In fact, we must assume that our assumptions about the nature of existence are indeed false.

Given how little we know about the nature of the universe it would be wrong to say with certainty that it works in a deterministic fashion. Perhaps it is just the audacity of human mind that assumes that there is such a thing as cause and effect. Though our view of the universe may be doomed never to describe reality, perhaps the strength of the human mind is that we ponder and hold belief in these complex, wondrous fables.