Sunday, May 01, 2005

On Science and Teleology, part II

In the previous installment of this essay I discussed the distinction between teleology and etiology, with teleology being the search for purposeful explanations and etiology being the search for causal explanations. I noted that one of criticisms of science is that it can not be used to find teleological explanations of phenomena and that it is limited to the realm of the etiological. I explored the question and offered some examples of questions that science, indeed, would not been well-suited to find teleological answers. I closed, however, by claiming that there were some questions that science could provide such an example for and that I had such an example… which I deferred from providing.

The example I had in mind is the phenomenon of play.

I could, at this point, try to give a technical definition of the word. Since this is Unstructured Musings, however, rather taking the risk of being sidetracking by a tricky definition, I'm going to take a shortcut and say that it's what you intuitively suppose that I'm talking about. Think of children playing with a ball or foals roughnecking with one another and you should know what sort of behavior I am referencing. If you suppose that this is cheating, all I can do if reference you to the behavior literature on the subject. I think that you'll find that the vast majority of papers will assume a common understanding between the authors and their readership.

Why do some creatures play?

The first think that we should ask ourselves is whether or not this is a well-formed teleological question. As I noted in the previous installment, not all "why" questions are really teleological questions. When we ask "why is the sky blue" we might well be asking whether there is a purpose to the blueness of the sky but we might also be asking for a causal explanation: what processes lead to the perception of blueness in the sky. Let us then reformulate the question so that we can be assured that we are not asking, for instance, for the casual chain of events that cause animals to play (e.g., the stimulation of certain neural clusters caused by the presence of certain environmental factors, etc): what is the purpose of play?

We are interested in knowing the meaning of play, so to speak, and why it is that certain beings engage in it (and, conversely) why others do not. We are not interested in the causality of play. Never the less, we will find our answer by way of etiological questions, although we will do so indirectly. The question, itself, is well-formed, however since our goal is, indeed, to seek a purposeful explanation.

One answer that immediately offers itself is the simple reply that the purpose of play is "fun". Animals and people play because it is fun to do so. This is a poor answer for two primary reasons.

The first reason is that the answer is non-informative. Of course we engage in play because it's fun. It's very nearly a tautology since "fun" is one of the aspects that define whether or not a particular behavior is play. The answer immediately leads us to wonder why play is fun. The sort of answer we are looking for &mdash an answer that illuminates the question in such a way as to grant us a fundamental insight into the purpose of play &mdash will have to be found at a deeper level.

The second reason that fun doesn't suffice as a teleological answer is that it is, in fact, an etiological answer. To say that we play because it is fun to play is to propose a causal chain. Adding some links to the chain will help to make this linkage explicit:

  • Engaging in the type of behavior known as play causes certain neurochemical interactions
  • These neurochemical interactions lead to the formation of the euphoric mental state known as "fun"
  • This euphoric state stimulates an organism's pleasure centers
  • This results in a feedback loop where an organism's desire to experience pleasure leads to it performing actions (play) which result in a euphoric brain-state (fun)
While this is almost certainly true, it doesn't do anything to give us insight into the actual purpose of play beyond a causal loop. We ought to bear in mind, of course, that there is no guarantee that there is a teleological answer to any given question. This causal loop could, in principle, be all the explanation that we could ever, even in principle, hope to find. The universe is not obligated to be purposeful.

Never the less, I believe that a purposeful (i.e., teleological) answer can be find and that it can be found by utilizing science to do so. More specifically, I believe that the best answer can be found in the realm of biology.

Those who may be familiar with either biology or teleology might suppose that I am going to utilize the theory of evolution. This is a reasonable guess given that evolutionary biology is, in fact, the one branch of science that produces the most, as well as the best, teleological explanations; however, I want to show how other branches of science can do so as well. The solution that I am seeking will be found in the sciences of genetics and embryology (with a bit of taxonomy) and should, in principle, be able to even convince a diehard creationist.

Before I proceed, I think that it's worthwhile to expand upon that a bit. A creationist will, of course, be inclined to offer the position that all questions should ultimately be answered in terms of God's will. I am reminded of a song I once heard that talks about the flowers and the hills, and so forth. Each stanza of the song ended with the words "because the Lord God made it so!"

We might suppose that if one thought that the answer to all questions was ultimately to be found in the will of God then science would, by definition, be excluded from providing any teleological answers; however, even if we do accept such a proposition it is still possible to ask (and answer) teleological questions that don't require us to resort to God by way of answer. Let me offer an example.

Suppose that I built a car and you wanted to know why the car included a break pedal. I could say that the break pedal is in the car because I so willed it. This would be a perfectly factual answer (and a teleological one at that!) but I suspect that you would find it uninformative. You aren't really interested in knowing who put the pedal there and you already know that whoever did put it there did so as an act of creative will. What you really want to know is the reason the car includes a break pedal. Simply saying that it is an expression of my will is uninformative. The answer you want is more likely to be something like this: the break pedal is there because it is a part of a system which allows the operator of the car to retard the car's momentum, thus allowing the driver to more easily drive the car without causing it to crash.

This second explanation is an example of a "functional teleology". Note that even though we sincerely believe that the car has a creator, we can find a satisfactory explanation that doesn't requires us to make reference to the creator. In doing so, we are neither denying nor affirming the existence of the creator (nor offering any comment upon additional teleological layers to the question).

Many theists have adopted the supposition that science doesn't seek divine answers to be a tacit endorsement of atheism. As we can see in this example, this is a poor assumption. Science seeks functional answers. Just as the question of a car's break pedal demonstrates that functional answers can be informative and even preferred, science strives for functional explanations precisely because such explanations are informative and useful. The fact that science doesn't try to seek explanations in the realm of the metaphysical or the theological does not mean that science is taking a stance on either subject &mdash quite the contrary.

As for the question at hand, if it is your preference to view play as, ultimately, being an expression of the will of God, so be it. I will only attempt to approach the question from the perspective of a functional teleology while leaving the matter of God's will (and existence) for some other time.

Let us begin our investigation into the question of play with a survey. We do so because it is evidence that many organisms do not engage in play. Fanciful tales to the contrary, plants do not play, nor do protozoans, fungi, amoebas, and so forth. Play is strictly limited to the kingdom of animals.

We can exclude from consideration those animals that lack brains such as starfish and sponges, or which only have the most rudimentary of brains such as insects and mites. Rather than proceeding in a haphazard way, let us do a more methodical survey using cladistics.

Cladistics is the science of partitioning the natural world into hierarchical groups (that is, into a taxonomy). At this point, some may believe that I'm about to break my promise of offering a teleology that would even satisfy a creationist. While modern cladistics does rely heavily upon evolutionary theory, even creationist theories utilize taxonomic relationships (all cats are felines, all felines are mammals, are mammals are vertebrates, etc). Indeed, the father of biological taxonomy (which later became cladistics), was a creationist (by necessity, being a predecessor of Darwin's). Since I'm only using cladistic partitions to help us narrow our search, I have not broken my word.

Being vertebrates we have a natural tendency to divide the animal world into vertebrates and invertebrates; however, this is largely the result of a parochial perspective. The vast majority of animals are invertebrates. Vertebrates aren't even a phylum (the largest taxonomic division among groups of animals) but rather a subphylum of chordates. For us to see animals as being divided by vertebration would be like the citizens of the island of Tonga dividing the people of the world into Tongans and non-Tongans.1 While this is a factual division, I suspect most people would be amused to suppose that being a non-Tongan said anything significant about them. Be that as it may, let's indulge our parochialism and first consider invertebrates if only to dispense with a large chunk of candidates.

The phenomenon of play does not appear to be a part of invertebrate (that is, 16/17ths of the world's phyla) behavior. Of all the invertebrate species, the only potential case might be octopuses (and yes, folks, that is a proper pluralization of the word octopus). Although octopuses are very remarkable creatures that exhibit some truly extraordinary behaviors &mdash including the ability to open sealed jars and to escape from fish tanks &mdash the only examples I've found for play among them is strictly anecdotal. To the best of my research, I haven't found any credible observations of octopus play and am inclined to view the anecdotal accounts with deep suspicion.

Let us narrow the focus to our own little corner of the biological world and consider play about those creatures that have a spinal column.

Do fish play? It seems not. How about amphibians? No. Perhaps reptiles? No. Birds? Apparently not, although they do engage in complex behaviors that sometimes seem to have a near resemblance.

Mammals do play. More precisely, some mammals play. Many mammals do not.

At this point, rather than trying to survey the various orders of mammals (which would be a huge task), I'm going to reformulate the question by asking what types of mammals play. For this purpose, I'm going to take a random sample of creatures that do and do not play and ponder the question of what, if anything, distinguishes them.2

Before doing so, however, I am going to give you the opportunity to do the same. See if you can identify any patterns that distinguish between mammals that play and mammals that do not. Meanwhile, I will pick up the thread during the next installment, two weeks hence.

1 Some might protest that vertebrates are special given that all large animals are vertebrates. Discounting such extinct examples such as a six foot long sea scorpion, it is true that having vertebrae is a definite advantage when it comes to size. However, this is nothing more than picking a particular feature and extolling it arbitrarily. Besides, the very largest organisms aren't animals at all, they're plants &mdash which certainly don't have vertebrae.

2 Hint: I'm not necessarily looking at the species level.

No comments:

what is this?

Tell me when this blog is updated. . .