Causation in Metaphysics

Danny Witwer: But it's not the future if you stop it Ð'- isn't that a fundamental paradox?

John Anderton: Yes, it is. You're talking about pre-determination which happens all the time. (He rolls a ball off of a table.) Why did you catch that?

Witwer: Because it was going to fall.

Anderton: You're certain?

Witwer: Yeah.

Anderton: But it didn't fall. You caught it. The fact that you prevented it from happening does not change the fact that is was going to happen.

-Minority Report

The 2002 Steven Spielberg film Minority Report centers around a futuristic police unit specializing in preventing murder which is foreseen by three unique human beings known as the pre-cognitives. These pre-cogs see the future and "tell" the officers of the murder through a series of images. The members of the pre-crime unit, as it is called, then prevent this murder from ever occurring.

The fundamental piece of this system of causality lies in the fact that an event is necessitated by its cause. The example shown above illustrates this: someone rolls a ball off of a table and, had someone else not prevented the ball from falling, the ball would necessarily have fallen off of the table. This is what is called a modal view of causation. However, this statement is problematic; to say that an event would have necessarily happened barring some other event does not make the resulting effect seem all that necessary. How is one to know that some other factor, such as a strong gust of wind, could not have interrupted the process of the ball falling as well? Quantum physics tells us that we do not even have proof that the ball won't up and disappear and reappear in some other part of the universe, as unlikely as this seems. But if causality is not based on the necessary succession from one causal event to another, what is it based on? Causation has always been a complex subject to be analyzed, and rightly so. There are seemingly endless theories which could be said to explain causation; it seems arriving at one definitive answer is near impossible. Unlike other scientific endeavors, causation is a problem which cannot be solved absolutely because it is an inherently mental process.

The 18th century thinker David Hume provided philosophy with one of the first non-modal models for causation. Hume believed that two events which others would have seen as cause and effect are no more related than the fact that they are temporally and/or spatially proximal. To illustrate his model, Hume uses the example of one billiard ball, ball a, hitting another, ball b. When one observes the ball a striking ball b and ball b concurrently moving in the same direction that ball a was, the initial impression would be that the balls colliding caused ball b to move from its initial rest. In reality the two events merely happen conjunctively. This is because Hume is an empiricist; he believes there is nothing human beings can think of which is not experienced via sense data or our own introspection regarding this sense data. All that is observed of the first ball hitting the second and the second entering a state of motion is that they occur conjunctively in space and time Ð'- there is no causal power, no indicator that one event was the cause and the other an effect, which is perceived.

However, it cannot be denied that humans do function within a causal world. If one is hungry then one eats; it could be said that the cessation of hunger is caused by eating. If one takes a step he will be spatially shifted to where the step indicated, caused by the physical laws relating to the bottom of his shoes and the ground. Hume solves this problem with the following assertion:

The mind has a great propensity to spread itself on external objects and to conjoin with them any internal impressions, which they occasion, and which always make their appearance at the same time that these objects make their appearance to the senses (Loux 191).

As stated before, Hume believes that everything a mind is capable of is produced through sense data or reflection and mental manipulation of this sense data. If there is no causal power ever perceived with the senses, yet one operates as if this power existed Ð'- that is, the causal power exists somewhere in the mind Ð'- then it must follow that this power is a result of the reflection upon the sense data of temporally and spatially conjunct events. (Yes, I realize the incongruity in using necessity to describe non-modal causation.) Simply put, what human beings view as causality is a construct of the mind, the mental product of continuously-observed conjoined events.

For an example, posit a child, and as is the case with children, this child is operating without Ð'- or at best with a severely rudimentary and undeveloped Ð'- mental model of causality. This child now places his hand on the hot coil of an electric stove range and is burned. He now has an example of two events which, to him, have caused each other, as his touching the coil was simultaneous with the pain in his hand. Later he touches the stove again, and is again burned. Through his own mental conditioning, the child soon learns that touching the coil is often temporally proximal with the burning of his hand; he has attributed a cause to the pain which he perceives, and it seems that whenever one touches the coil one's hand is burned. But then one day he observes his parent placing their hand on the coil, only to see that they have not recoiled in pain. He is confused by this and attempts to further examine the phenomena, finding that the coil is cold and does not burn his flesh. His causal model is now modified to reflect this new observation. The same can be said for science. It was once thought that the application of leaches to one's skin caused one to recover from illness because this was observed to have occurred a number of times, but our causal model has since been modified to not include this causal power. It is presently believed that the Human Immunodeficiency Virus is the cause of the disease AIDS, but it is possible that this causal power could be rejected in the future, changing what we once believed to be scientific fact about the cause of AIDS.

Now, saying that the notion of causality lies solely in the mental realm does not mean that this mental causality does not have form or organization. The state of the matter is quite the opposite in fact. Each human has a causal model built into his mind, and each of these models is unique, but like human beings themselves, these models have an underlying