In the past, there had been a large gap between the principles that applied to physics and chemistry, and those of the life sciences. This is especially true in the field of psychology and behavioral science. The lack of understanding about the brain left open-ended questions regarding behaviorism, personality, intelligence, and mental disease. However, I believe enough progress has been made to make predictions and interpretations about philosophical questions using a “hard science” lens. Naturally, the idea of free will comes into question. Although practical experience seems to suggest we have free will, in reality, our behaviors and actions are the result of the same forces that drive all natural processes in predictable ways.
Accepting the possibility of living without freewill is easier when discussing small, simple, animals and plants. Take an amoeba, for example. Let us imagine that I have this organism on a slide and am peering down through a microscope. Using a small metal probe, I can touch this single cell’s outer surface, and in doing so, the organism will retract. I can repeat this procedure over and over again, obtaining the same result each time. From my perspective, it appears that I am eliciting a response from the amoeba because of my actions, while from the amoeba’s perspective, it is reacting to a stimulus felt on its exterior, and nothing more. To say that the amoeba is making a conscious decision to react to the prod of the probe is bordering on the absurd. As such, it is more accurate to suggest that the amoeba is not able to “control” its actions in the classic sense, for when we look at its physiology, we can map out the chemical chain of events that lead up to the amoeba’s “decision” to retract itself from the stimulus. In this manner, the decision to “retract” was never a decision. Instead, it was inevitable.
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| Image: istockphoto/Janne Ahvo |
Looking at life through a chemist’s eyes, we see that the motifs behind living things (moving, thinking, responding, etc) can be explained by simplifying these elements to their most basic form. For example, let us explain a complex behavior, such asseeing a piece of fruit and then deciding whether to walk towards it or not, using this logic. To start, electromagnetic radiation in the form of visible light travels from the fruit, into the pupils of the subject, eventually striking the retina in the back of the eye. When this light is absorbed by proteins of rhodopsin embedded in the cell membrane of rod cells, the protein releases smaller protein fragments which, through chemical reaction cascades, leads to the polarization of nerve cells (opposite of “regular neurons”), that, in turn, excite neurons in the optic nerve. The optic nerve, through the thalamus, transmits these visual stimuli to the visual cortex. From there, various signals from the cortex are integrated by different parts of the brain, eventually leading to the interpretation that the information it is receiving equates to a piece of fruit sitting on a table about five feet away. So far, all of these procedural steps can be explained and predicted using the same chemical principles that allow a scientist to predict whether a material will rust, “spontaneously” combust, turn, pink, and so on. However, how the subject reacts is still left unexplained, and is a topic of debate in free will arguments. Will the subject “decide” to walk over to the fruit and take a bite? Or will the subject decide to walk away from the fruit, allowing the fruit to exercise its free will to remain on the table?
We can take this line of questioning further, exhausting all the different possibilities of action the subject can take, but this is not needed. What is important in this discussion is whether the subject has the freedom to make any one of the infinite decisions in front of him. As in the case of the amoeba, I argue that we react to stimuli in a predictable way, and as such, are not granted the luxury of free will. Here, the only difference between the decision tree of the amoeba and that of a human is that the number of variables influencing a human’s decision to pick up the fruit is far greater than the number of variables influencing the amoeba to retract itself from the prod of a metal probe. Maybe the subject has been conditioned to avoid the fruit because of an allergic reaction he/she experienced to fruit in the past. Perhaps the subject has learned from countless public service announcements that fruit is good for the body, and so he/she decides to take a bite. Further still, perhaps the subject had his heart broken by a girl wearing a skirt with a bountiful pattern of various seasonal fruits, and as such, the subject feels depressed and remains at a distance. In any case, if we know what variables are the most important in relation to the decision at hand, we can predict with certainty the behavior of the subject in response to not only stimuli, but thoughts, emotions, sensations, and feelings as well.
A fun, yet gruesome example of explaining our lack of free will is by thinking of a person without a brain. We take this unenlightened “person” and put his lungs on a ventilator, use a cardiopulmonary bypass pump to keep his blood flowing, and we start a central line that keeps the rest of his cells happy and metabolized, so to speak. We then use a simple test to determine whether this person is intact by conducting a knee jerk reflex test (the test where a doctor uses a soft hammer and hits a specific tendon in the kneecap, resulting in a brief, and reflexive, movement in the lower leg). Applyingthis same technique to our patient, we find that the subject’s leg responds in the usual manner, as the neuronal circuitry that produces the reflex is contained within the spinal cord. Although the subject responded, we cannot argue that our headless volunteer has evoked his free will to make the decision to move his leg. Instead, the movement in his leg was a consequence of anatomy and physiology.
Now, let us give our subject an eye, with anoptic nerve thatis directly attached to the top of the spinal cord and is, by nature of its hypothetical design, only able to react to the presence or absence of light. Furthermore, let us say that when no light is present, the subject’s body remains in equilibrium (in a seated position), and when light is present, the subject raises his right arm. When no light is present, light does not enter the pupil and therefore an electric signal is not transmitted from the eye, through the optic nerve, and through the spinal cord to the neuromuscular junctions of various motor groups of the arm. However, when a light bulb is turned on, the subject’s arm goes up. In this case, we would still say that the subject is not exercising his free will. If we give the subject ears (and the appropriate neuronal infrastructure to integrate sound) that respond to high-pitched sound by moving his toes, we would still say that the subject is not “using” his free will to make the decision to move his toes. We could continue adding on more and more complex anatomical structures that accept stimuli and, in turn, produce a particular behavior, but this is not necessary, as no matter how complex these structures (e.g. the amygdala) and responses (e.g. laughing) come, they all can be reduced down to a biochemical process that can (or will eventually be) rationalized and explained.
It is impossible to have “free will”. What control we think we might have over our lives is the result of conditioning from our upbringing, our perceptions of the world, and our ability to interact with objects, ideas, and people around us. But living without free will is without moral quandary, as we have been doing this our entire lives. As Voltaire’s character, Candide, said, “We must cultivate our garden”. In doing so, we will add to our “decision trees” a wider range of possibilities, situations, thoughts, behaviors, feelings, emotions, actions, and solutions, all from which we will never be able to freely choose.
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