From Bacteria to Bach and Back

Darwin is often credited with overthrowing Aristotle’s all-too-influential doctrine that everything in the world has a purpose, an “end” (in the sense that the ends justify the means), or as the French say, a raison d’être, a reason for being.

Aristotle identified four questions we might want to ask about anything:

1.What is it made of, or its material cause?

2.What is its structure, or its formal cause?

3.How did it get started, or what is its efficient cause?

4.What is its purpose, or its final, or telic, cause?

The Greek for the fourth cause is telos from which we derive the term teleology. Science, we are often told, has banished the telos, and we have Darwin to thank for this. As Karl Marx (1861) once famously put it, in his appreciation of Darwin’s Origin of Species: “Not only is a death blow dealt here for the first time to ‘Teleology’ in the natural sciences but their rational meaning is empirically explained.”

But a closer look shows that Marx is equivocating between two views that continue to be defended:

We should banish all teleological formulations from the natural sciences

now that we can “empirically explain” the “rational meaning” of natural phenomena without ancient ideology (of entelechies, Intelligent Creators and the like), we can replace old-fashioned teleology with new, post-Darwinian teleology.

This equivocation is firmly knitted into the practice and declarations of many thoughtful scientists to this day. On the one hand, biologists routinely and ubiquitously refer to the functions of behaviors such as foraging and territory marking, organs such as eyes and swim bladders, subcellular “machinery” such as ribosomes, chemical cycles such as the Krebs cycle, and macromolecules such as motor proteins and hemoglobin. But some thoughtful biologists and philosophers of biology are uneasy about these claims and insist that all this talk of functions and purposes is really only shorthand, a handy metaphor, and that strictly speaking there are no such things as functions, no purposes, no teleology at all in the world. Here we see the effect of another of the imagination-distorting forces spawned by Cartesian gravity. So seductive is the lure of Cartesian thinking that in order to resist it, some think we should follow the abstemious principle that whenever there is any risk of infection by prescientific concepts—of souls and spirits, Aristotelian teleology and the like—it is best to err on the side of squeaky-clean, absolute quarantine. This is often a fine principle: the surgeon excising a tumor takes out a generous “margin” around the suspect tissue; political leaders institute buffer zones, to keep dangerous weapons—or dangerous ideologies—at arm’s length.

A little propaganda can help keep people vigilant. Among the epithets hurled at unrepentant teleologists are “Darwinian paranoia” (Francis 2004; Godfrey-Smith 2009) and “conspiracy theorists” (Rosenberg 2011). It is of course open to defend an intermediate position that forbids certain teleological excesses but licenses more staid and circumscribed varieties of talk about functions, and philosophers have devised a variety of such views. My informal sense is that many scientists assume that some such sane middle position is in place and must have been adequately defended in some book or article that they probably read years ago. So far as I know, however, no such consensus classic text exists,⁹ and many of the scientists who guiltlessly allude to the functions of whatever they are studying still insist that they would never commit the sin of teleology.

One of the further forces in operation here is the desire not to give aid and comfort to creationists and the Intelligent Design crowd. By speaking of purpose and design in Nature, we (apparently) give them half their case; it is better, some think, to maintain a stern embargo on such themes and insist that strictly speaking nothing in the biosphere is designed unless it is designed by human artificers. Nature’s way of generating complex systems (organs, behaviors, etc.) is so unlike an artificer’s way that we should not use the same language to describe them. Thus Richard Dawkins speaks (on occasion—e.g., 1996, p. 4) of designoid features of organisms, and in The Ancestors’ Tale (2004) he says, “the illusion of design conjured by Darwinian natural selection is so breathtakingly powerful” (p. 457). I disagree with this overkill austerity, which can backfire badly. A few years ago I overheard some Harvard Medical School students in a bar marveling at the intricacies to be found in the protein machinery inside a cell. One of them exclaimed, “How could anybody believe in evolution in the face of all that design!” The others did not demur, whatever their private thoughts. Why would anyone say that? Evolutionists aren’t embarrassed by the intricacy of Nature. They revel in it! Discovering and explaining the evolution of the intracellular complexities that govern the life of a cell has been one of the glories of evolutionary microbiology in recent years. But this fellow’s remark suggests that one of the themes gaining ground in common understanding is that evolutionary biologists are reluctant to “admit” or “acknowledge” the manifest design in Nature. People should know better, especially medical students!

Consider in this regard Christoph Schönborn, Catholic archbishop of Vienna, who was seduced by the Intelligent Design folks into denying the theory of natural selection on the grounds that it couldn’t explain all the design. He said, notoriously, in a New York Times op-ed piece entitled “Finding Design in Nature” (July 7, 2005):

The Catholic Church, while leaving to science many details about the history of life on earth, proclaims that by the light of reason the human intellect can readily and clearly discern purpose and design in the natural world, including the world of living things. Evolution in the sense of common ancestry might be true, but evolution in the neo-Darwinian sense—an unguided, unplanned process of random variation and natural selection—is not. Any system of thought that denies or seeks to explain away the overwhelming evidence for design in biology is ideology, not science.

Which battle do we want to fight? Do we want to try to convince lay people that they don’t really see the design that is stunningly obvious at every scale in biology, or would we rather try to persuade them that what Darwin has shown is that there can be design—real design, as real as it gets—without an Intelligent Designer? We have persuaded the world that atoms are not atomic, and that the Earth goes around the Sun. Why shrink from the pedagogical task of showing that there can be design without a designer? So I am defending here (once again, with new emphasis) the following claim:

The biosphere is utterly saturated with design, with purpose, with reasons. What I call the “design stance” predicts and explains features throughout the living world using the same assumptions that work so well when reverse-engineering artifacts made by (somewhat) intelligent human designers.

There are three different but closely related strategies or stances we can adopt when trying to understand, explain, and predict phenomena: the physical stance, the design stance, and the intentional stance (Dennett 1971, 1981, 1983, 1987, and elsewhere). The physical stance is the least risky but also the most difficult; you treat the phenomenon in question as a physical phenomenon, obeying the laws of physics, and use your hard-won understanding of physics to predict what will happen next. The design stance works only for things that are designed, either artifacts or living things or their parts, and have functions or purposes. The intentional stance works primarily for things that are designed to use information to accomplish their functions. It works by treating the thing as a rational agent, attributing “beliefs” and “desires” and “rationality” to the thing, and predicting that it will act rationally.

Evolution by natural selection is not itself a designed thing, an agent with purposes, but it acts as if it were (it occupies the role vacated by the Intelligent Designer): it is a set of processes that “find” and “track” reasons for things to be arranged one way rather than another. The chief difference between the reasons found by evolution and the reasons found by human designers is that the latter are typically (but not always) represented in the minds of the designers, whereas the reasons uncovered by natural selection are represented for the first time by those human investigators who succeed in reverse engineering Nature’s productions. Dawkins’s title, The Blind Watchmaker (1986), nicely evokes the apparently paradoxical nature of these processes: on the one hand they are blind, mindless, without goals, and on the other hand they produce designed entities galore, many of which become competent artificers (nest-builders, web-spinners, and so forth) and a few become intelligent designers and builders: us.

Evolutionary processes brought purposes and reasons into existence the same way they brought color vision (and hence colors) into existence: gradually. If we understand the way our human world of reasons grew out of a simpler world where there were no reasons, we will see that purposes and reasons are as real as colors, as real as life. Thinkers who insist that Darwin has banished teleology should add, for consistency’s sake, that science has also demonstrated the unreality of colors and of life itself. Atoms are all there is, and atoms aren’t colored, and aren’t alive either. How could mere large conglomerations of uncolored, unalive things add up to colored, live things? This is a rhetorical question that should be, and can be, answered (eventually). Now I want to defend the claim that there are reasons for what proteins do, and there are reasons for what bacteria do, what trees do, what animals do, and what we do. (And there are colors as well, of course, and yes, Virginia, life really exists.)

Different senses of “why”

Perhaps the best way of seeing the reality, indeed the ubiquity in Nature, of reasons is to reflect on the different meanings of “why.” The English word is equivocal, and the main ambiguity is marked by a familiar pair of substitute phrases: what for? and how come?”

“Why are you handing me your camera?” asks what are you doing this for?

“Why does ice float?” asks how come: what it is about the way ice forms that makes it lower density than liquid water?

The how come question asks for a process narrative that explains the phenomenon without saying it is for anything. “Why is the sky blue?” “Why is the sand on the beach sorted by size?” “Why did the ground just shake?” “Why does hail accompany thunderstorms?” “Why is this dry mud cracked in such a fashion?” And also, “Why did this turbine blade fail?” Some folks might wish to treat the question of why ice floats as inviting a what for reason—God’s reason, presumably—for this feature of the inanimate world. (“I guess God wanted fish to be able to live under the ice in the winter, and if ponds froze from the bottom up, this would be hard on the fish.”) But as long as we have an answer to the how come question, in terms of physics and chemistry, it really would be something like paranoia to ask for more.

Compare four questions:

1.Do you know the reason why planets are spherical?

2.Do you know the reason why ball bearings are spherical?

3.Do you know the reason why asteroids aren’t spherical?

4.Do you know the reason why dice aren’t spherical?

The word “reason” is acceptable in all four questions (at least to my ear—how about yours?), but the answers to (1) and (3) don’t give reasons (there aren’t any reasons); they give causes, or process narratives. In some contexts the word “reason” can mean cause, unfortunately. You can answer questions (2) and (4) with process narratives along the lines of “well, the ball bearings were made on a lathe of sorts, which spun the metal … and the dice were cast in boxlike molds …” but those are not reasons. Sometimes people confuse the different questions, as in a memorable exchange that occurred in a debate I had with an ardent champion of Skinnerian behaviorism, Lou Michaels, at Western Michigan University in 1974. I had presented my paper “Skinner Skinned” (in Brainstorms 1978), and Michaels, in his rebuttal, delivered a particularly bold bit of behaviorist ideology, to which I responded, “But why do you say that, Lou?” to which his instant reply was “Because I have been rewarded for saying that in the past.” I was demanding a reason—a what for—and getting a process narrative—a how come—in reply. There is a difference, and the Skinnerians’ failed attempt to make it go away should alert positivistically minded scientists that they pay a big price in understanding if they try to banish “what for.”

The first two sentences of this book are “How come there are minds? And how is it possible for minds to ask and answer this question?” It is asking for a process narrative, and that is what I am going to provide. But it will be a process narrative that also answers the questions how come there are “what for?” questions, and what are “what for?” questions for?

The evolution of “why”: from how come to what for

Evolution by natural selection starts with how come and arrives at what for. We start with a lifeless world in which there are no reasons, no purposes at all, but there are processes that happen: rotating planets, tides, freezing, thawing, volcanic eruptions, and kazillions of chemical reactions. Some of those processes happen to generate other processes that happen to generate other processes until at some “point” (but don’t look for a bright line) we find it appropriate to describe the reasons why some things are arranged as they now are. (Why do we find it appropriate, and how did we get into that state of mind? Patience, the answer to that will come soon.)

A central feature of human interaction, and one of the features unique to our species, is the activity of asking others to explain themselves, to justify their choices and actions, and then judging, endorsing, rebutting their answers, in recursive rounds of the “why?” game. Children catch on early, and often overdo their roles, trying the patience of their parents. “Why are you sawing the board?” “I’m making a new door.” “Why are you making a new door?” “So we can close the house up when we go out.” “Why do you want to close the house up when we go out?” … “Why don’t we want strangers taking our things?” … “Why do we have things?” The fluency with which we all engage in this mutual reason-checking testifies to its importance in conducting our lives: our capacity to respond appropriately in this reason-checking activity is the root of responsibility. (Anscombe 1957) Those who cannot explain themselves or cannot be moved by the reasons offered by others, those who are “deaf to” the persuasions of advisors, are rightly judged to be of diminished responsibility and are treated differently by the law.

This activity of demanding and evaluating each other’s reasons for action does not occupy our every waking hour, but it does play a major role in coordinating our activities, initiating the young into their adult roles, and establishing the norms by which we judge one another. So central is this practice to our own way of life that it is sometimes hard to imagine how other social species—dolphins, wolves, and chimpanzees, for instance—can get along without it. How do the juveniles “learn their place,” for instance, without being told their place? How do elephants settle disagreements about when to move on or where to go next? Subtle instinctual signals of approval and disapproval must suffice, and we should also remember that no other species engages in the level of complex cooperative behaviors that we human beings have achieved.

Wilfrid Sellars, a philosopher at the University of Pittsburgh, described this activity of reasoning with one another as creating or constituting “the logical space of reasons” (1962) and inspired a generation of Pittsburgh philosophers, led by Robert Brandom and John Haugeland, to explore this arena in detail. What are the permissible moves, and why? How do new considerations enter the space, and how are transgressions dealt with? The space of reasons is bound by norms, by mutual recognition of how things ought to go—the right way, not the wrong way, to play the reason-giving game. Wherever there are reasons, then, there is room for, and a need for, some kind of justification and the possibility of correction when something goes wrong.

This “normativity” is the foundation of ethics: the ability to appreciate how reason-giving ought to go is a prerequisite for appreciating how life in society ought to go. Why and how did this practice and its rules arise? It hasn’t existed forever, but it exists now. How come and what for? The Pittsburgh philosophers have not addressed this question, asking how “it got that way,” so we will have to supplement their analysis with some careful speculation of our own on the evolution of the reason-giving game. I will try to show that ignoring this question has led the Pittsburgh philosophers to elide the distinction between two different kinds of norms and their associated modes of correction, which I will call social normativity and instrumental normativity. The former, analyzed and celebrated at Pittsburgh, is concerned with the social norms that arise within the practice of communication and collaboration (hence Haugeland [1998] speaks of the “censoriousness” of members of society as the force that does the correcting). The latter is concerned with quality control or efficiency, the norms of engineering, you could say, as revealed by market forces or by natural failures. This is nicely illustrated by the distinction between a good deed and a good tool. A good deed might be clumsily executed and even fail in its purpose, while a good tool might be an efficient torture device or evil weapon. We can see the same contrast in negative cases, in the distinction between naughty and stupid. People may punish you for being naughty, by their lights, but Nature itself may mindlessly punish you for being stupid. As we shall see, we need both kinds of norms to create the perspective from which reasons are discernible in Nature.

Reason-appreciation did not coevolve with reasons the way color vision coevolved with color. Reason-appreciation is a later, more advanced product of evolution than reasons.

Wherever there are reasons, an implicit norm may be invoked: real reasons are supposed always to be good reasons, reasons that justify the feature in question. (No demand for justification is implied by any “how come” question.) When we reverse engineer a newly discovered artifact, for instance, we may ask why there is a conspicuous knob in the corner that doesn’t seem to “do anything” (anything useful—it makes a shadow when light falls on it, and changes the center of gravity of the artifact, but has no apparent function). We expect, until we learn otherwise, that the designer had a reason, a good reason, for that knob. It might be that there used to be a good reason, but that reason has lapsed and the manufacturers have forgotten this fact. The knob is vestigial, functionless, and present only because of inertia in the manufacturing process. The same expectations drive the reverse-engineering explorations of living things, and biologists often permit themselves to speak, casually, about what “Nature intended” or what “evolution had in mind” when it “selected” some puzzling feature of a living thing.10 No doubt the biologists’ practice is a direct descendant of the reverse engineering of artifacts designed and made by other human beings, which is itself a direct descendant of the societal institution of asking for and giving reasons for human activities. That might mean that this practice is an outdated vestige of prescientific thinking—and many biologists surmise as much—or it might mean that biologists have found a brilliant extension of reverse engineering into the living realm, using the thinking tools Nature has endowed us with to discover real patterns in the world that can well be called the reasons for the existence of other real patterns. To defend the latter claim, we need to take a look at how evolution itself could get going.

Go forth and multiply

In Darwin’s Dangerous Idea (1995), I argued that natural selection is an algorithmic process, a collection of sorting algorithms that are themselves composed of generate-and-test algorithms that exploit randomness (pseudo-randomness, chaos) in the generation phase, and some sort of mindless quality-control testing phase, with the winners advancing in the tournament by having more offspring. How does this cascade of generative processes get under way? As noted in the last chapter, the actual suite of processes that led to the origin of life are still unknown, but we can dissipate some of the fog by noting that, as usual, a variety of gradual processes of revision are available to get the ball rolling.

The prebiotic or abiotic world was not utter chaos, a random confetti of atoms in motion. In particular there were cycles, at many spatio-temporal scales: seasons, night and day, tides, the water cycle, and thousands of chemical cycles discoverable at the atomic and molecular level. Think of cycles as “do-loops” in algorithms, actions that return to a starting point after “accomplishing” something—accumulating something, or moving something, or sorting something, for instance—and then repeating (and repeating and repeating), gradually changing the conditions in the world and thus raising the probability that something new will happen. A striking abiotic example is illustrated by Kessler and Werner in Science 2003.

These stone circles would strike anyone as a highly improbable scattering of stones across the landscape; it looks “man-made”—reminiscent of the elegant outdoor sculptures by Andy Goldsworthy—but it is the natural outcome of hundreds or thousands of mindless cycles of freezing and thawing on Spitsbergen in the Arctic. New England farmers have known for centuries about frost driving a “fresh crop” of stones up to the soil surface every winter; stones that have to be removed before plowing and planting. The classic New England “stone walls” we still see today along field edges and marching through former fields now reforested, were never meant to keep anything in or out; they are really not walls but very long narrow piles of boulders and small rocks hauled to the nearest part of the edge of the cultivated field. They are clearly the result of deliberate, hard human work, which had a purpose. Ironically, if the farmers hadn’t removed the stones, over many cycles of freezing and thawing the stones might have formed one of the “patterned ground” phenomena illustrated here, not always circles, but more often polygons, and sometimes labyrinths and other patterns. Kessler and Werner provide an explanation of the process with a model—an algorithm—that produces these different sorting effects by varying the parameters of stone size, soil moisture and density, temperature, speed of freezing, and hillslope gradient. So we have a pretty good idea how come these phenomena exist where they do, and anybody who encountered these stone circles and concluded that there had to be a purposeful artificer behind them, an answer to the what for question, would be wrong.

In the abiotic world, many similar cycles occur concurrently but asynchronously, wheels within wheels within wheels, with different periods of repetition, “exploring” the space of chemical possibility. This would be a variety of parallel processing, a little bit like the mass production of industry, which makes lots of different parts in different places at different rates of production and then brings them together for assembly, except that this abiotic mass production is utterly unplanned and unmotivated. There is no differential re-production in the abiotic world, but we do get varieties of differential persistence: some temporary combinations of parts hang around longer than others, thereby having more time to pick up revisions and adjustments. The rich can get richer, in short, even though they can’t yet bequeath their riches to descendants. Differential persistence must then somehow gradually turn into differential reproduction. The proto-Darwinian algorithms of differential “survival” of chemical combinations can give rise to auto-catalytic reaction cycles that in turn give rise to differential replication as just a special case of differential persistence, a very special case, a particularly explosive type that multiplies its advantage by … multiplication! It generates many near-duplicate persisters, which can then “explore” many more slightly different corners of the world than any one or two persisters could do.

“A diamond is forever” according to the advertising slogan, but that is an exaggeration. A diamond is magnificently persistent, much more persistent than its typical competition, but its persistence is simply modeled by its linear descent through time, Tuesday’s diamond being like its parent, Monday’s diamond, and so forth. It never multiplies. But it can accumulate changes, wear and tear, a coating of mud that hardens, and so forth, which may make it more or less persistent. Like other durable things, it is affected by many cycles, many do-loops that involve it in one way or another. Usually these effects do not accumulate for long but rather get wiped out by later effects, but sometimes a barrier happens to get erected: a wall or membrane of some sort that provides extra shielding.

In the world of software, two well-recognized phenomena are serendipity and its opposite clobbering. The former is the chance collision of two unrelated processes with a happy result, and clobbering is such a collision with a destructive result. Walls or membranes that tend for whatever reason to prevent clobbering will be particularly persistent and will permit internal cycles (do-loops) to operate without interference. And so we see the engineering necessity of membranes to house the collection of chemical cycles—the Krebs cycle and thousands of others—that together permit life to emerge. (An excellent source on this algorithmic view of chemical cycles in cells is Dennis Bray, Wetware 2009.) Even the simplest bacterial cells have a sort of nervous system composed of chemical networks of exquisite efficiency and elegance. But how could just the right combination of membranes and do-loops ever arise in the prebiotic world? “Not in a million years!” some say. Fair enough, but then how about once in a hundred million years? It only has to happen once to ignite the fuse of reproduction.

Imagine we are back in the early days of this process where persistence turns gradually into multiplication, and we see a proliferation of some type of items where before there were none and we ask, “Why are we seeing these improbable things here?” The question is equivocal! For now there is both a process narrative answer, how come, and a justification, what for. We are confronting a situation in which some chemical structures are present while chemically possible alternatives are absent, and what we are looking at are things that are better at persisting in the local circumstances than their contemporary alternatives. Before we can have competent reproducers, we have to have competent persisters, structures with enough stability to hang around long enough to pick up revisions. This is not a very impressive competence, to be sure, but it is just what the Darwinian account needs: something that is only sorta competent, nothing too fancy. We are witnessing an “automatic” (algorithmic) paring away of the nonfunctional, crowded out by the functional. And by the time we get to a reproducing bacterium, there is functional virtuosity galore. In other words, there are reasons why the parts are shaped and ordered as they are. We can reverse engineer any reproducing entity, determining its good and its bad, and saying why it is good or bad. This is the birth of reasons, and it is satisfying to note that this is a case of what Glenn Adelson has aptly called Darwinism about Darwinism (Godfrey-Smith 2009): we see the gradual emergence of the species of reasons out of the species of mere causes, what fors out of how comes, with no “essential” dividing line between them. Just as there is no Prime Mammal—the first mammal that didn’t have a mammal for a mother—there is no Prime Reason, the first feature of the biosphere that helped something exist because it made it better at existing than the “competition.”

Natural selection is thus an automatic reason-finder, which “discovers” and “endorses” and “focuses” reasons over many generations. The scare quotes are to remind us that natural selection doesn’t have a mind, doesn’t itself have reasons, but is nevertheless competent to perform this “task” of design refinement. Let’s be sure we know how to cash out the scare quotes. Consider a population of beetles with lots of variation in it. Some do well (at multiplying); most do not. Take the minority (typically) that do well, reproductively, and ask about each one: why did it do better than average. Our question is equivocal; it can be interpreted as asking how come or what for. In many cases, most cases, the answer is no reason at all; it’s just dumb luck, good or bad. In which case we can have only a how come answer to our question. But if there is a subset, perhaps very small, of cases in which there is an answer to the what for question, a difference that happens to make a difference, then those cases have in common the germ of a reason, a proto-reason, if you like. The process narrative explains how it came about and also, in the process, points to why these are better than those, why they won the competition. “Let the best entity win!” is the slogan of the evolution tournament, and the winners, being better, wear the justification of their enhancements on their sleeves. In every generation, in every lineage, only some competitors manage to reproduce, and each descendant in the next generation is either just lucky or lucky-to-be-gifted in some way. The latter group was selected (for cause, you might say, but better would be for a reason). This process accounts for the accumulation of function by a process that blindly tracks reasons, creating things that have purposes but don’t need to know them. The Need to Know principle made famous in spy novels also reigns in the biosphere: an organism doesn’t need to know the reasons why the gifts it inherits are beneficial to it, and natural selection itself doesn’t need to know what it’s doing.

Darwin understood this:

The term “natural selection” is in some respects a bad one, as it seems to imply conscious choice; but this will be disregarded after a little familiarity. No one objects to chemists speaking of “elective affinity”; and certainly an acid has no more choice in combining with a base, than the conditions of life have in determining whether or not a new form be selected or preserved.… For brevity sake I sometimes speak of natural selection as an intelligent power;—in the same way as astronomers speak of the attraction of gravity as ruling the movements of the planets.… I have, also, often personified Nature; for I have found it difficult to avoid this ambiguity; but I mean by nature only the aggregate action and product of many natural laws,—and by laws only the ascertained sequence of events. (1868, pp. 6–7)

So there were reasons long before there were reason-representers—us. The reasons tracked by evolution I have called “free-floating rationales,” a term that has apparently jangled the nerves of some few thinkers, who suspect I am conjuring up ghosts of some sort. Not at all. Free-floating rationales are no more ghostly or problematic than numbers or centers of gravity. Cubes had eight corners before people invented ways of articulating arithmetic, and asteroids had centers of gravity before there were physicists to dream up the idea and calculate with it. Reasons existed long before there were reasoners. Some find this way of thinking unnerving and probably “unsound,” but I am not relenting. Instead I am hoping here to calm their fears and convince them that we should all be happy to speak of the reasons uncovered by evolution before they were ever expressed or represented by human investigators or any other minds.11 Consider the strikingly similar constructions in figures 3.3 and 3.4 of the color insert following p. 238.

The termite castle and Gaudí’s La Sagrada Familia are very similar in shape but utterly different in genesis and construction. There are reasons for the structures and shapes of the termite castle, but they are not represented by any of the termites who constructed it. There is no Architect Termite who planned the structure, nor do any individual termites have the slightest clue about why they build the way they do. This is competence without comprehension, about which more later. There are also reasons for the structures and shapes of Gaudí’s masterpiece, but they are (in the main) Gaudí’s reasons. Gaudí had reasons for the shapes he ordered created; there are reasons for the shapes created by the termites, but the termites didn’t have those reasons. There are reasons why trees spread their branches, but they are not in any strong sense the trees’ reasons. Sponges do things for reasons, bacteria do things for reasons; even viruses do things for reasons. But they don’t have the reasons; they don’t need to have the reasons.

Are we the only reason-representers? This is a very important question, but I will postpone an answer until I have provided a wider setting for the perspective shift I am proposing here. So far, what I take to have shown is that Darwin didn’t extinguish teleology; he naturalized it, but this verdict is not as widely accepted as it should be, and a vague squeamishness leads some scientists to go overboard avoiding design talk and reason talk. The space of reasons is created by the human practice of reason-giving and is bound by norms, both social/ethical and instrumental (the difference between being naughty and being stupid). Reverse engineering in biology is a descendant of reason-giving-judging.

The evolution of what for from how come can be seen in the way we interpret the gradual emergence of living things via a cascade of prebiotic cycles. Free-floating rationales emerge as the reasons why some features exist; they do not presuppose intelligent designers, even though the designs that emerge are extraordinarily good. For instance, there are reasons why termite colonies have the features they do, but the termites, unlike Gaudí, do not have or represent reasons, and their excellent designs are not products of an intelligent designer.

9Biologists and philosophers have written often about function talk, and although there are persistent disagreements about how to license it, there is something of a consensus that evolutionary considerations do the trick one way or another for natural functions, and facts about both history and current competence anchor attributions of function to artifacts. For a good anthology of the best work by both biologists and philosophers, see Allen, Bekoff, and Lauder 1998.

10For instance, biologist Shirley Tilghman, in the 2003 Watson Lecture, said: “But clearly, what is immediately apparent when you look at any part of those two genomes that have been compared is that evolution has indeed been hard at work, conserving far more of the genome than we could explain by genes and their closely allied regulatory elements.… Scientists should have a field day trying to understand what evolution had in mind when she paid so much attention to these little segments of DNA.”

11Philosophers who are skeptical about my intransigence on this score might like to read T. M. Scanlon’s recent book, Being Realistic about Reasons (2014), for an exhaustive and exhausting survey of the problems one confronts if one ignores engineering reasons and concentrates on having moral reasons for action.