Evolving Thoughts

Objections to evolution from the particular perspective of religion come in three forms: the problem of creation, the problem of purpose and the problem of chance. All other objections are general philosophical ones, and I’ll discuss them under that heading.

The problem of creation

The majority of believers in the world either think God created the universe or shaped it from some prior substance. Consequently, when a scientific explanation reduces some previously divine work to natural phenomena, religious sensibilities are raised. Only the so-called “Abrahamic” religions – Judaism, Christianity and Islam and their offshoots – are truly creationist in the sense that they believe God created the universe out of nothing, or as it is expressed in theological Latin, creatio ex nihilo, but all religions have a role for God or the gods making some things, especially humans.

This raises an immediate problem: if science tells us, based on evidence and explanation, that something that was thought to be the work of God is a natural process, it has both the effect of reducing God’s effective action and undercutting some of the reason for believing in God. This is the problem of naturalism, or making natural what was God’s domain. The term “naturalism”, however, is ambiguous. On the one hand it can mean giving a natural explanation through the use of scientific methods such as the use of human reasoning and observation. Or, it can mean the claim that only “natural” things exist. The first is sometimes called “methodological naturalism”, and it is the underpinning of all science, and indeed all learning about the world. The second is sometimes called “metaphysical naturalism”, although I think it is instead a claim about what exists (which is called “ontology” amongst the philosophical community). God might be natural in that sense. There is no real sharp dividing line between the natural and the supernatural that would satisfy most believers. For example, human nature for some is held to include a soul, which is divine. So let us call the second kind ontological naturalism.

“Nature” is a very variable word. It can mean many things, including the world apart from human intervention, or it can mean what is physical, or it can mean the underlying causes of behaviours (as in “human nature”. So when a philosopher or theologian talks about “naturalism”, it pays to pay attention to what they think it contrasts with. In theology it often means what is not divine, that is, what is not supernatural. However, theology, at least in the Islamic-Christian tradition, has several alternative accounts of God’s actions and cause. One of these is called “occasionalism”, a view devised by the Muslim philosopher al-Ghazali in the 11th century: there is no natural cause for anything. If you light a match and it burns, it is because God made it do so, not because matches are made from chemicals that tend to burn when struck. Few Christian thinkers accept this, however, and they often make a different distinction: between primary and secondary causes.

A secondary cause is a usual natural cause. Matches burn because they are made from stuff that ignites when struck. But the existence of that stuff is God’s doing. This is the primary cause. The idea that God is the primary cause of what exists, comes from an idea of Aristotle’s, the Greek philosopher. He thought that nothing changed (“moved”) unless something acted on it. Since it is clear that change occurs in a regular way, then what makes this thing change must have been, in its turn, moved by something else. The Greeks didn’t much like infinity, and so there must, he reasoned, have been a first mover; it had to terminate in something that was, of its nature, in motion. Incidentally, this is what made Newton’s first law so radical:  he thought the exact opposite of Aristotle, that things tend to move (in a straight line) unless they are stopped by something from doing so.

With this in hand, we can ask if things are caused by something to exist. Another argument from the Muslim thinkers is the so-called Kalam Argument. According to this view, which is championed today by William Lane Craig, if we observe that something has a cause, then it has to have had a cause in its own fashion, and so on. This implies to Craig that there had to have been a cause for everything that exists, by extrapolation from what we observe. Critics say that a cause within a universe is one thing, a cause of a universe is another. As David Hume, the 18th century Scottish philosopher noted, you can’t make inferences from things you observe in the universe to the universe itself.

This of course doesn’t stop people from trying. That subsection of physics known as “cosmology” offers explanations of our universe as something generated by prior or larger universes in what is called the “multiverse”, a staple of many bad science fictions shows. But this is untestable (so far) and anyway it just pushes the issue back a step. In such arguments, you can simply replace “universe” with “multiverse”.

But none of this has anything much to do with evolution. There is a common misunderstanding that evolution is about the origins of the universe or of life itself. In fact, modern evolutionary theory is about what happens after both events. For the origins of life, you have to go to the chemists and geologists, who have not so much a lack of theories as too many theories. Every second month, it seems, there is another way that life could arise published in the literature, all of which are quite feasible. In such cases, we know that it is possible that life could arise naturally, but we may never know exactly how it did. If there were only one feasible way that life could arise, then we could have some confidence in that explanation being true, but as it is we have partial explanations for what might even be separate steps in the origin of life. They may all be true, and what life we now see is what “won”. At least one philosopher has proposed that there might be “life” now we don’t even notice, because it uses vastly different chemistry from our own, but this is so far just a supposition.

So the real issue for theology with evolution has to do with the idea that there are things in the universe that are the result of a natural process, and in particular living things, and in particular again, us. Almost everyone (except occasionalists) think that some things naturally cause other things. So we can take that as read. If you don’t think that, then science itself becomes impossible, and we are no longer able to argue about the issue. The beginnings of science can be found in the very early Greek speaking philosophers who thought that things had natures, and were not just the actions of gods on whim. This was a major break with previous ideas. It made possible attempts (very crudely at first) to explain why things happened, rather than simply repeating “the gods did it”, which, as it applies to everything that possibly could happen, explains precisely nothing. But if things have natures, that is, internal properties that cause them to behave as they are seen to behave, then the task of the natural philosopher (which is what scientists were called before that term was invented in the 19th century) is to uncover these natures. This permits us to predict how they will behave, such as predicting what will burn and under what conditions, or when an eclipse might occur. This allows us to manipulate these things.

Of course, all learning about the world, whether scientific in a formal manner or not, involves observing it, and well before science evolved this is how we learned to make spears, smelt iron, grow crops and breed animals for our purposes. But prescientific thinking often invented “explanations”, like the Chinese notion of Chi or the idea there is a “vital force” in living animals, which turned out not to have any real scientific basis. We can have useful knowledge without understanding it. A good example is the case of Balinese agriculture before the arrival of Europeans. Over hundreds of years, the Balinese planted rice and diverted water according to a Hindu calendar of festivals, but when the Europeans came, they inserted European techniques. However, these techniques did not take into account the special developmental requirements of rice, and the result was a series of poor crops and erosion. The Hindu system contained knowledge (justified by theological narratives and festivals) that made Balinese agriculture successful. Nobody “knew” this knowledge, but it worked because the festivals were modified to make it work over many years. The explanations offered, however, were not themselves scientific.

Likewise, in the Bible, and right up until the invention of modern genetics, it was common “knowledge” that the experience of a pregnant animal would affect its progeny’s characteristics. In Genesis 30:37-43, Jacob tricks Laban by placing striped and speckled poles before the stronger breeding sheep and cattle so they would be striped and speckled, and he would get them under the terms of his agreement with Laban. Likewise, as late as Darwin you find accounts by breeders of experience of the mother affecting the progeny. Yet, for all these errors, breeders were still able to breed varieties of quite remarkable diversity, as the pigeons Darwin bred indicate. So the explanations of the success is quite different from the explanations we now hold to be true in our best science.

So it does not follow that all our knowledge is based on science, nor that all we do know was gained through the use of scientific method. We gain knowledge by trial and error, but we do not always understand why it is knowledge. The idea that all knowledge is based on science, and that religion is not a way of knowing, is far more complex than it may seem. All knowledge is gained by trial and error through observation, but it need not be the case that the religious explanations are correct. Nor need they be false in one way: they can encode information gained that way.

That said, the conflict between religious stories, sometimes called etiologies (from the Greek for “causes” or “accounts”), and science can be severe. People have a great emotional commitment to stories that play a role in traditions, and which serve to shore up communal identity. In particular, they find scientific reductions of ideas like the origins of life, of species, and of humans in particular very challenging. This is understandable. Similar things happen in other domains as well, such as national myths. While this is psychologically understandable, it isn’t philosophically interesting: it gets called “psychologism” in those debates. Psychologism is the view that our psychology is the same thing as our knowledge or logic. Philosophers distinguish between what we want to think and what we should if we are being reasonable. Even though we may wish things to be one way, if reason and evidence points in another direction, we should follow them, not our preferences. As Bishop Butler wrote in the 18th century:

Things and actions are what they are, and consequences of them will be what they will be: why then should we desire to be deceived? [Bishop Joseph Butler, Fifteen Sermons, Sermon VII, §16.]

The interventionist belief

All religions bar a few rather philosophical varieties have God or the gods intervening in the “natural” order. This is because gods are agents, which is to say they have goals and purposes and act to realise them. Some religions have inactive gods (Epicurus’ gods contemplated their own perfection, and had no interest in the finite and imperfect world) but almost all the religions that people follow have active deities.

Many people accept that evolution occurs, but deny that it happens naturally, at least when God’s purposes are involved. Darwin himself argued (in the final chapter of the Variation) that evolution was independent of God’s interventions, when debating his friend and defender, the Christian botanist Asa Gray, who held that God intervened in evolution to make humans come out as the end product, by making the right chance mutations occur. Darwin’s response was that this would undercut the whole point of evolution by natural selection, since selection is the “designer” and not the processes (which he didn’t understand, since mutation was not known at the time) that provided the building blocks.

The idea that God intervened, as a micromanager would in ensuring that their staff delivered the “right” outcomes, is sometimes called “theistic evolution” or TE. This is a widely held view. Strict naturalists think of it as a kind of creationism, and it is, but not in the usual sense of God creating species ex nihilo. It is creationist in the sense that God is the primary cause of all that is, and occasionally a secondary cause of individual events. In short, it is an occasional occasionalism. We’ll address God’s purposes in the next post, but for now let’s consider the role of causation here.

Saving creation, Darwin and naturalism

“Darwinian” evolution is the idea that events cause variation on which natural selection acts to modify a population to become better adapted to the “conditions of life”, or the environment in which that population lives. This is not to say that every change that happens to a population is the result of natural selection. A process known as genetic drift is caused when the next generation randomly samples the genes of the past generation, and the sample is not representative of the genes that existed. However, what is often called “Darwinian” evolution is natural selection, so we’ll focus on this.

It is possible to set up a situation where the “right” mutations exist so that an outcome can be forced by natural selection, so long as you also know the conditions in which the population will live. This can be, and has been, done experimentally and in computer simulations. But for God to do it, he needs to know that the mutations exist, and what the environment is in which they will be selected, as well as the size and distribution of the population. This involves there being a world in which the right conditions happen.

So God would need to ensure these conditions and mutations. It is well understood that in natural terms mutations are chance events. A mutation occurs when for one reason or another a gene is copied incorrectly in a number of ways. These are chance events, but not uncaused – every mutation is caused by surrounding conditions, which might be a chemical, or a radiation particle, or just thermal energy acting on the molecule at replication (that is, when the DNA molecule is duplicated when a cell divides).Also, he would need to ensure that the environment is what it needs to be. Since all these things are caused by physical processes ranging from weather, incoming meteors, geological processes, an so on, nothing remains to be explained in other than physical terms.

The sense of “chance” will be explored later, but for now it means, roughly, that an event cannot be predicted. God, however, has no such limitations: He can predict how things will turn out, because he has complete information and no limits on how much computing he can do, by definition. So if things are caused in a predictable fashion, God can design a world in which all these things will happen as he wants, without intervention.

But what if he cannot? What if, for example, quantum events are unpredictable even in theory? Could God create a world in which Darwinian accidents occur such that they will lead to the goals he has in mind? I think he could, and here is my argument:

Suppose God can simulate entire universes in his mind. As an analogy, suppose God has a supercomputer on which he can simulate all possible universes or worlds, the way we now simulate evolution on computers. Computers are generally determined: they run programs in a way that the results are forced by the programming. However, when simulations of evolution are run on computers, they often introduce a degree of randomness by using a RAND() function. These, in our computers are only pseudorandom; they are not properly random. But presumably God has either a truly random function, or his pseudorandom function is in every observable respect random to those within the universe.

Now God can simulate any universe, and so he runs full simulations for all possible universes, and picks the one that best meets his providential goals. This is, according to Gottfried Wilhelm Leibniz,a 17th century philosopher and polymath, “the best of all possible worlds”. This was parodied by Voltaire in his novel Candide, but Leibniz never said that every event in the world was optimal, only that the whole universe was, so it allows for there to be individual cases of evil and tragedy within it.

So God runs either a very large number of simulations or all possible simulations including those with random events, picks the best world, and makes it real (pours in the ontological cement, as it were). In this world, we have fully Darwinian accidents, a contingent evolutionary process, but it’s a world that realises God’s goals. This is a kind of higher level kind of theistic evolution. God is not a micromanager on this account, but truly a creator. This would permit God to be a creator of Darwinian accidents and secondary causes, without contradicting God’s role as primary cause.

This allows theists to be both committed to natural science and the basic beliefs of creation.

Next, I will consider the problem of purpose.