On the Origin of Intelligence
Quite often, in recent months, I have found myself caught in the middle of heated debates between proponents of special human creation, on the one hand, and astronomical optimists, on the other, in regards to the existence of intelligent extraterrestrial life. Proponents of special human creation quite often argue that human consciousness and intelligence could not possibly have arisen naturally, that it is impossible for such things to be properties of solely physical processes, and that they are therefore justified in claiming that it is entirely inconceivable that intelligent extraterrestrial life could exist in the universe. You can find this view very commonly espoused by Young Earth Creationists, Old Earth Creationists, and Intelligent Design proponents, alike (for example, check out this recent article by noted Young Earther, Ken Ham). On the opposite side of the fence, you’ll quite frequently hear both amateur and professional astronomy enthusiasts proclaiming that the physical cosmos is so inordinately vast that it is absolutely inconceivable that intelligent extraterrestrial life doesn’t exist in the universe. Such advocates often spout off statistics regarding the number of stars in the observable universe, facts about the abundance of the primary chemical building-blocks of life, and various iterations of the Drake Equation.
Almost invariably, I find myself getting yelled at by both sides of these arguments, because I disagree with both of their positions.
This might sound paradoxical, at first. How can one disagree with both of these ideas? Surely, one or the other must be correct! However, this is fairly easily shown to be a false dichotomy. If one claims that it is inconceivable for intelligent extraterrestrial life to exist, the opposite of that claim is that it is conceivable for intelligent extraterrestrial life to exist. Furthermore, to say that it is conceivable for intelligent extraterrestrial life to exist is not the same as claiming that it is inconceivable that intelligent extraterrestrial life might not exist. Put another way, given the proposition , one camp is saying that cannot possibly be true, while the other claims that cannot possibly be false. I am claiming that it is possible for to be true, and it is possible for to be false, and that we do not currently have enough data to eliminate either of these possibilities from contention.
What is even meant when we utilize the word “intelligence?” Most people have a fairly vague understanding of what is meant by the word, but it is very difficult to assign it a rigorous definition– which, in turn, tends to obfuscate any sort of discussion on the matter. In general, we tend to have a very anthropomorphic view of “intelligence.” That is to say, most people would consider intelligence to be something along the lines of “thinking and creating in the manner that humans do.” We consider complex things like linguistic symbolization, mathematical understanding, and technological development to be indicators of intelligence. In fact, these are the exact factors which are utilized by most programs involved in the Search for Extraterrestrial Intelligence. For example, many such programs are attempting to locate narrow-band radio transmissions which convey nonrandom data patterns through space. They are looking for these things because humans have constructed methods of generating radio transmissions, have analyzed and understood nonrandom patterns, and have communicated these through symbols. We have no idea how we might even recognize any sort of intelligence which does not operate in this manner.
So, then, how is it that humanity developed these abilities? If we can answer this question, we can get far closer to establishing how probable it is that these things might develop elsewhere in the universe.
Now, it is absolutely true that the universe is mind-bogglingly large, and that occurrences which would seem incredibly rare, on a normal human scale, are therefore more likely to occur repeatedly on a cosmological scale. Our current best estimates place the number of stars in the known universe at about , which means that an event which only affects one in a million stars would still affect 100,000,000,000,000,000 stars. That’s 100-quadrillion stars. Just to put that into perspective, imagine counting up every strand of hair on the head of every one of the seven billion human beings alive on Earth, today. Then multiply that number by 100. We are talking about an inordinately vast universe in which these things are occurring.
Given that the universe is inordinately vast, is it therefore reasonable to claim that intelligent extraterrestrial life almost certainly exists elsewhere in the universe? Not at all. Multiplying the many scenarios which led to the human developments of symbolic language, mathematical understanding, and advanced technology quickly leads to probabilities which are easily as insanely small as the universe is ridiculously large. Our development of these things came as a direct result of the exact position in space occupied by the Earth. You may have heard some people talk about “Goldilocks zones” for planets, before. This refers to a precise range of distance from a star which a planet could possibly occupy in order to foster both an atmosphere and the liquid water which are necessary for life as we know it– not too close, nor too far, but just right. This habitable zone is only the tip of the astronomical iceberg, however. Even if a planet is in this zone, there is no guarantee that it actually has an atmosphere and liquid water. Even if it has these, there’s no guarantee that the planet’s formational chemistry would be suitable to a process of abiogenesis. Even if abiogenesis occurred, there is no guarantee that this life would survive. Even if the life survived, there’s no guarantee that random mutation would lead to an evolutionary path suitable to life which can observe the world around it. Even if observing life evolved, there’s no guarantee that this life would similarly evolve the cognitive capacity to understand its observations, nor the mental capability to analyze them, nor the verbal attenuation to express them, nor the manual dexterity to record them.
We have an enormous moon, proportional to our planet, whose gravitational influence over the Earth directly led to the regularities which were necessary for the human discovery of methods for reckoning time and seasons. We have an atmosphere which is transparent enough to allow us to view the cosmos while being opaque enough to shield us from deadly radiation. We occupy a location in our galaxy far enough from the central core that we are not overly flooded with the light from other stars, which would prevent us from observing the universe. We have an atmosphere which is conducive towards the manipulation of fire, dry surface land on which life could thrive, and an abundance of accessible metals– all of which are necessary for the construction of complex tools.
This is only a very, very small sample of all the enormous factors that eventually led to our development of “intelligence,” as it is being sought by SETI programs. It is very easy to see how multiplying all of these probabilities together can very quickly lead to a number which reaches or exceeds the stars which exist in the known universe. I find it absolutely conceivable that human intelligence truly is unique in the cosmos.
That said, I do not agree with Creationists and Intelligent Design proponents who purport that all of these same factors which I have listed point to the impossibility of human intelligence having arisen without the intercession of an outside agency. This is commonly referred to the “fine tuning” argument for the existence of God. Since it is so incredibly improbable that all of these factors would occur in so precise a manner as to result in our particular situation, proponents of the “fine-tuning” argument claim that it must, therefore, be the result of a directed and deliberate action which was intended to produce this exact result. This is, of course, fallacious as it necessarily conflates two completely different– and mutually exclusive– concepts: improbability and impossibility. No matter how infinitesimally small the odds, anything which is improbable is still possible. Conversely, a thing which is impossible cannot be assigned any non-zero probability, and therefore cannot be considered an improbable event. The proponents of the “fine-tuning” argument do a great deal of work to show that a particular set of occurrences is improbable; however, they then make the illogical leap to the conclusion that it is impossible. I once watched a friend roll five 20-sided dice, and all five resulted in the number 1 showing on their top face. That is an incredibly improbable result– only 1 in 3.2 Million. Given how often I watch a person roll that many D20’s, it is insanely unlikely that I should have ever witnessed this event. However, improbable does not equate to impossible. No matter how improbable a thing is, it still maintains some small quantitative probability, and is therefore not impossible.
As such, even if one were to multiply all of the insanely many factors which led to our development of intelligence to find that the probability of their occurrence was equal-to-or-less-than in (meaning that it would be quite likely human intelligence is unique in the universe), this would not imply that it is therefore impossible for human intelligence to be non-unique. After all, the probability of all those occurrences happening twice, regardless of how small the number actually is, would still be non-zero and, therefore, possible. As such, I reject the claim that it is inconceivable for intelligent extraterrestrial life to exist.
Either humanity is completely alone in this universe in our intellectual capabilities, or else we are not. I see absolutely no reason to think that either of these cases is impossible. As such, I disagree both with the Creationists who overstate the improbability of the development of intelligent life, and with the astronomical optimists who understate that same improbability.