Random and Non-Random Phenomena in Science
In the foregoing discussion, we have established the following methodological principle of science: Whenever any phenomenon exhibits an observable, persistent, significant deviation from random behavior, without any observable cause, then we are justified in inferring the existence of an unseen force or entity as the cause of the phenomenon. We now need to go further and to ask whether there is any principle of science that can tell us what is probable and what is improbable. Probable configurations or phenomena are those that are most likely random; whereas, improbable configurations are more likely to result from the action of some invisible force (when, of course, there is no observable cause).
There is indeed such a principle. It is the second law of thermodynamics (the so-called entropy principle), first put forth by the French engineer Carnot (1796–1832) and the German physicist Clausius (1822–1888). We will consider two statements or formulations of this law, one informal and heuristic, the second more precise and formal. However, both formulations are scientifically correct.
The first statement is: Disorder is probable and order is improbable. Or, with a bit more elaboration: Order, structure, and complexity are improbable; while disorder, simplicity, and uniformity are probable. On a commonsense level we can see why this is true: for, order represents a few specific configurations; whereas, any logically possible configuration represents disorder. Let us pursue this point a bit further.
Suppose we compare a pile of bricks and a well-built brick house. The pile of bricks represents disorder and the brick house represents order. If we want to transform a brick house into a pile of bricks, brick by brick, we can do this in any logically possible way. We can take any brick for the first brick, any brick for the second brick, and so on. All possibilities lead to a pile of bricks. But if we want to transform a pile of bricks into a brick house, we cannot do this in any possible way. We cannot, for example, place any upper brick before we have placed a certain appropriate number of lower bricks. Thus, transforming a brick house into a pile of bricks represents a process that leads from order to disorder, or from the improbable towards the probable. And transforming a pile of bricks into a well-built brick house represents a process that leads from disorder to order, i.e., from the probable towards the improbable.
Thus, if we built a brick house in the woods and left it to the forces of nature for fifty years, we would not be surprised to find that the house had degenerated into a pile of bricks. But if we left a pile of bricks under the same conditions for fifty years, we would be very surprised to find a well-built brick house in its place. The surprise we would feel in such a case represents our intuition of the truth of the second law of thermodynamics.
Let us now give the second, more formal statement of the law. We begin with a few definitions. By a physical system we mean any physical entity (object) or any collection of such entities. The entities that make up a physical system are its components, and any collection of components of a system forms a subsystem. An isolated physical system is one that receives no energy from outside the system. We now state: in any isolated physical system, disorder will increase. Moreover, if the system remains isolated, then disorder in the system will increase until the state known as maximum entropy or total disorder is attained. This is a stable state of the system in that, once attained, no further change will occur unless energy is furnished to the system from the outside, in some appropriate manner. Informally stated: Any system degenerates towards disorder if “left to itself.”
This formulation of the second law of thermodynamics leads naturally to the question of whether or not there are any truly isolated physical systems. As far as we know, there are no totally isolated systems (unless the whole physical universe is a closed system, which may or may not be the case). For example, most of the energy of the solar system comes from the sun, but there is some radiation and energy input from outside the solar system. However, there are many relatively isolated systems, and in these systems the operation of the second law of thermodynamics has always been confirmed. Indeed, this law is one of the most universally verified and highly validated of all laws and principles of science.
One very important point should be stressed here. The second law of thermodynamics states that any isolated system will necessarily degenerate towards disorder, but this does not exclude the possibility that non-isolated systems may also degenerate! To avoid degeneration towards disorder, it is not usually sufficient just to furnish raw energy to the system. Energy must be furnished in such a way, and in such a form, that the system can convert some of the energy into order (or use the energy to complexify its structure). How such a thing may happen will depend on the nature of the system itself (the relationships that exist between the components within the system), the way the system evolves, and the way it interacts with the outside.
Let us give two examples. The Brownian motion of air molecules in a closed room is assumed to be totally random. Suppose a bottle of a highly volatile perfume is unstoppered in this room. The initial configuration, with all the perfume in the bottle, represents order. Once the perfume is released and begins to volatilize, the Brownian motion of air molecules will rather quickly spread the perfume until it is uniformly distributed throughout the room. This is the natural degeneration towards disorder, wholly explainable by the random nature of Brownian motion. Suppose, now, that we modify the experiment by adding radiant heat from a source outside the room. The increased air temperature in the room will only increase the speed of the Brownian motion, thereby hastening the spread of the perfume (and thus the degeneration towards disorder of the system). In this case, the input of energy from outside the system will not result in any evolution towards order.
As a second example, consider the growth (complexification) of leaved plant systems on the earth. Such growth depends on the process of photosynthesis within the leaf subsystem of the plant. Photosynthesis uses direct sunlight as an outside energy source. If sunlight were eliminated entirely and replaced by another form of energy (say, heat), the growth of those plants would not occur. Thus, the internal structure of a leaved plant allows it to utilize a certain form of outside energy (direct sunlight) to increase its complexity, thus, to evolve towards greater order. But other forms of energy input may not result in growth and complexification (indeed, excessive or inappropriate energy input may well destroy the system).
Thus, the observable world (visible reality) is composed of physical systems. Some are evolving from less probable to more probable states; some are (more or less) static or stable; and some are evolving from more probable to less probable states. Systems of the first type can be understood as the result of a random process. The stable systems are either in a state of maximum entropy or else maintained in a constant (or periodically fluctuating) state by means of continual inputs of energy from outside (e.g., the dissipative systems of Prigogine [Prigogine and Stengers, Order Out of Chaos]). Those that exhibit evolution from more probable to less probable states cannot be the result of a random process. The cause of such a growth pattern can only be some observable input of energy (e.g., plant growth on earth that is fuelled by solar energy) or else some nonobservable (invisible) force. It is this latter case that we will now consider.
Let us now think of all the physical systems in the observable universe and ask which of these systems is the most complex, the most highly ordered, the most structured. The answer is clear and unequivocal: It is the human being, and in particular the human brain and central nervous system, which, beyond any possible doubt, constitute the most sophisticated set of behaving entities in the known universe (see, for example, the series of four volumes The Neurosciences). According to any standard of comparison, and with regard to any known physical system, natural or artificial, the physical human being is by far the most highly ordered and complex. In the following, unless otherwise noted, whenever we speak of the human being, we will mean the physical human being and not the human being in any metaphorical, cultural, or spiritual sense.
We can already draw a first conclusion: Since the human being is the most highly ordered structure in the known observable universe, the human being is the most improbable of all physical systems and thus the least likely to have been produced by a random process. So, let us take a look at the process that did produce the human being— the process we call evolution.
First, we need to establish the facts (as far as we know them) of the process of evolution. The observables of the phenomenon of evolution are primarily the fossil record, found in the layers of sediment in various locations all over the earth. If there were contradictions or ambiguities in this record, we would have a major problem in interpreting these data. However, such is not the case. All these sedimentary layers show the same basic configuration, namely, that higher, more complex forms of life followed simpler, less complex forms. In other words, the process of evolution was a process of complexification, of moving from relative simplicity and disorder towards relative complexity and order. It was therefore a process of moving from more probable configurations towards less probable configurations.
Although we can easily become involved in intricate discussions about exactly how long the physical universe, the solar system, or the earth have existed, or how long conditions for life existed on earth before life actually appeared, the basic pattern is unequivocally clear. The earth has existed for some billions of years (many expert opinions fix the age of the earth at about 4.5 billion years). The first, and most rudimentary, life forms are thought to have been blue-green algae, which may have appeared as early as 2 billion years ago. In any case, following the initial appearance of the algae, there was a long period (perhaps a billion years) during which they remained the only life forms. After the algae became abundant, other early forms of plant life appeared.
Through radioactive dating and other methods, it has been established with a high degree of certainty that the first crude forms of invertebrate animal life could not have appeared earlier than about 600 million years ago. Thus, the process of evolution, from one-celled animals to the emergence of the mature human being (about 50,000 years ago), took no longer than 600 million years, which, from the geological perspective, is a fairly short time-span. This shows that there was no time for anything like an “unlimited” or “open-ended” experimentation in evolution. Moreover, it is estimated that roughly a thousand species intervened between the appearance of one-celled organisms and the mature human being. In each case, the transition from one species to another was a process leading from a lower (and therefore more probable) to a higher (and thus less probable) configuration. Finally, the evidence from the fossil record consistently shows that evolution was not a smooth, gradual process. Rather, there were long periods of stasis and stability (the so-called plateaus), punctuated by much shorter periods of rapid change (towards complexification).
Thus, evolution is clearly an example of a process that exhibits a significant, persistent deviation from randomness. Within a specified and limited time-frame, there was a persistent and recurrent movement from more probable to less probable configurations. It is therefore unscientific and irrational to attribute this process to chance. Indeed, just the transition from one species to the next could, if left to chance, take about as long as the lifespan of the earth itself, and to account for the whole evolutionary process we would have to multiply this figure by a thousand, yielding a figure much greater than the estimated lifespan of the entire universe (from the “beginning” until the present).
In the light of these considerations, we have a scientific right—indeed we are compelled by the logic of scientific methodology—to conclude that the process of evolution is the result of the action of some unobservable force. In particular, we human beings are the “end product” of evolution and thus owe our existence to this force. It seems reasonable to call this force “God,” but anyone uncomfortable with that name can simply call it “the evolutionary force” (or, more precisely, “the force that produced evolution and thus produced the human being”). Moreover, it is most reasonable to suppose that the force of evolution is different from all other forces that science has so far discovered or hypothesized, because according to our present knowledge, no other force could have produced the phenomenon of evolution.7
Now, just as in the case of gravity, a skeptic can refuse to accept the existence of the evolutionary force by choosing to believe that evolution was a random process, a series of highly unlikely coincidences; but in making such a choice the skeptic relinquishes any claim to be acting scientifically or rationally. From the point of view of scientific methodology, one must always choose the most likely among all known, logically possible alternatives. Although it is logically possible that evolution was a random process, it is clearly not the most likely possibility. Such a skeptic, especially a practicing scientist, needs to explain why he or she accepts and follows this basic principle of scientific methodology elsewhere but makes an exception in the case of evolution. If one has no trouble believing in gravity or the strong nuclear force, based on evidence of a kind similar to that for the evolutionary force, then why irrationally resist belief in the force of evolution?
We claim to have fulfilled our intention of giving a scientific proof of God’s existence. We have shown, on the basis of an observable phenomenon (the coming into existence of the human being), that the existence of a non-observable cause is the most reasonable of all known logical possibilities. However, one could well ask the following further question: to what extent are we justified in calling the motive force of evolution “God”? Why do we not call gravity or the strong nuclear force “God”? We deal with this issue in the following section.
The Nature of God
For the remainder of this discussion, let us accept as established the existence of an unseen force that is the cause of the process of evolution and thus of the human being, the end product of this process. It might seem at first that our identification of such a cause with God is rather arbitrary and gratuitous. However, a little reflection shows that this is not so.
To begin with, we know that this force is capable of producing a being having all of the subtlety and refinement that we humans are capable of exhibiting. We do not call gravity or the strong nuclear force “God” because the effects these forces produce are not so marvelous as the effect produced by the evolutionary force. In the same spirit that has motivated our basic approach throughout this article, we can ask whether or not it is reasonable to suppose that a force capable of producing an effect such as the human being is at least as subtle as humans. This hypothesis seems as reasonable as (if not more reasonable than) any other logical possibility.
In fact, we know certainly that this force is capable of doing at least one thing that we could never do, namely the bringing into being of the human race. Indeed, the human race did not even exist during all of the time that this force was driving evolution forward. We are the result of the action of this force, and we owe our existence to it. It has created us.
In our discussion of visible and invisible reality, we have already noted that, from the point of view of modern physics, invisible reality produces visible reality and, in fact, encompasses or surpasses visible reality. Thus, the invisible cause of evolution (and therefore of the human being) might also be plausibly supposed to encompass or surpass humans. In particular, we know from our own experience of ourselves that we have a conscious intellect and a free will. It is therefore not unreasonable that the force or entity which is the cause of our existence might also have such faculties as consciousness, intelligence, and will—and most probably to a degree much superior to us. The only alternative is to believe that a blind, unconscious force, devoid of any intelligence, has somehow brought into being a creature who is endowed with conscious intelligence.
Indeed, if we know anything at all, we know that we have a conscious subjectivity, because our knowledge of anything is mediated to us by this very subjectivity. Our subjectivity is thus the most basic condition of our existence. It is the inner space in which each of us lives, and we know that our subjectivity and our consciousness are the result of the action of this force. In this way, the knowledge of the nature of the force that has created us is most appropriately explored through a deeper knowledge of that which is most immediately accessible to us, i.e., our own inmost selves. It seems, therefore, that our knowledge of the existence and the nature of God is on the most solid foundation it could possibly be.