When I made that first post about Tyler Cowen’s monograph on marginalism – Tyler Cowen has thrown in the towel and is waiting for the machines to take over – I had no specific plays about writing a series of posts about and occasioned by the book. A day later, with a post, Marginalism is a Rank 4 idea, along with thermodynamics and biological evolution, I had decided that, yes, “it looks like I’ll be doing a series of posts about the book, though I can’t say how long that series will be.” But I had no intention of writing as many posts as I have, much less a spin-off working paper, On Method: Computational Compressibility in Complex Natural and Cultural Phenomena.
This post is itself like that. I figured it for two, maybe three thousand words, but possibly less. Instead it’s just grown and grown to almost 8000 words (and I dropped a long appendix). There is a reason for that, which you can see in the title of that second post, where I assert that marginalism is a Rank 4 idea. That’s why this series of posts, and this post in particular, has grown. The objective in that second post was to situate marginalism in the context provided by the theory of cognitive evolution that David Hays began publishing in the 1990s starting with our basic paper, The Evolution of Cognition [1]. That’s where we set forth our basic conception that, over the long term, human culture has evolved through a series of architectures each grounded in specific informatic technology, starting with speech (Rank 1), writing (Rank 2), arithmetic calculation (Rank 3), and computation (Rank 4).
On the one hand, since I cannot assume familiarity with those ideas, I have to spend time developing some conceptual apparatus. At the same time I have the opportunity to extent the range of examples Hays and I have subjected to analysis with those ideas. That’s what I’m doing in this post.
In his Chapter 3, Cowen he has remarks about various pinnacles of human achievement, including two moments in the history of biological thinking, the emergence of modern taxonomy in the work of Carolus Linnaeus in the 18th century and the theory of evolution, by Charles Darwin, in the 19th century. I will argue that they represent Rank 3 and Rank 4 cognition, respectively. But I want to start with Rank 1 ethnobiology followed by the Rank 2 ordering of the biological world into a structure that has come to be know as the Great Chain of Being (in the West). This will give us the opportunity to follow one conceptual arena through the four cognitive ranks. Doing that, however, requires developing more conceptual apparatus than I had originally anticipated.
I want to start with how Cowen frames his treatments of botanical classification and evolution and then present some basic conceptual apparatus about processes of perception and cognition. Once those preliminaries have been taken care of we can take a look at the ethnological work on biological classification in Rank 1 (preliterate) cultures. Then we work our way through the other three ranks, commenting on Cowen’s remarks in connection with Ranks 3 and 4, and conclude with some further remarks about Cowen’s peculiar framing.
Cowen’s Framing
There are three aspects to how Cowen frames his various examples, starting, of course with marginalism: lateness, obviousness, and seeing around a corner.
Marginalism is late (p. 57):
To better understand the Marginal Revolution, we need to ask some fundamental questions about economics as a science. In particular, why did it take so long for economic reasoning to develop? I don’t even mean as a full, literal science, replete with advanced econometric methods, but simply as a general conceptual toolbox for intelligent people. The lateness of the Marginal Revolution is part of a broader story about the lateness of economic reasoning more generally.
Later (p. 59):
So I don’t think progress in economics has been slow in general. It is right now coming off an incredible 130-year or so run. Progress in economics, however, was glacial from the time of the ancient Greeks to the late 19th century, with a noticeable burst in the 18th century as well, centered around Adam Smith.
Here he combines all three of factors, peering around corners, obviousness, and then lateness (p. 62-63):
There is no “brute force” method for obtaining fundamental economic insight. Rather, you need to peer around a corner and see something that the other people have not already seen. And once you see and grasp it, you cannot easily forget it, again reflecting the asymmetry of this path toward knowledge. So often I have heard economists make proclamations like: “Once you start thinking about the world in economic terms, you can no longer unsee those things.”
That is exactly correct, but it is truly hard to see them in the first place. In essence, I think economics was so late to develop because it was so hard to peer around its corners. To see supply and demand in their proper workings.
Economics developed late because it is difficult to see around corners where the obvious truths are waiting to be found.
Now we have botanical classification, which Cowen introduces under this heading (p. 65): “Botanical Classification as a Laggard Science.” Then:
The history of botany is a parallel example to that of economics. Some key insights of botany seem fairly intuitive, at least once you understand them, yet they took a long time to develop. [...]
He goes on to remark about how botanical classification should be obvious:
You might think “botany is so simple – all you have to do is to look at a bunch of plants and give them names in some coherent system. They should have mastered this in the Dark Ages!” Surely plants are around us all, and observing them does not require complex equipment such as telescopes.
Cowen frames Darwin’s account of evolution in the same way (p. 76):
Theories of evolution and natural selection also are intuitive once you understand them, and they seem virtually inescapable once you are willing to consider them seriously. Yet they are remarkably late in becoming part of general human knowledge, and indeed to this day, according to polls a significant percentage of Americans still do not accept those doctrines.
Cowen seems to have some idea of the “proper” tempo at which ideas unfold in history but he never offers an explicit account of what this tempo is based on. Rather, he just offers examples of earlier intellectual and cultural high points, e.g. Greek philosophy, geometry and mathematics, Velasquez, Shakespeare, and Bach (pp. 59-61), as if botanical classification could have been cracked in Euclid’s time. Are we to suppose that biological evolution could have been discovered no later than Shakespeare’s lifetime if only someone had peered around the proper corners?
Before moving on to biology, however, I want to lay out some conceptual equipment from cognitive science.
Two Modes of Thought
Decade after decade discussions of thought and perception have settled around an opposition which is expressed in various pairs of terms. I first encountered it as analog vs. digital. In present discussions of AI it presents as neural vs. symbolic. Perhaps the deepest version is the one Miriam Yevick used in 1975, holographic vs. sequential [2]. In a paper David Hays and I published about metaphor we contrasted physiognomic vs. propositional [3].
Most linguistic reasoning exhibits the digital/symbol/sequential/propositional aspect of the opposition. As for the other side of the opposition, the analog/neural/holographic/physiognomic side, I offer this paragraph from the metaphor article that Hays and I wrote:
Our sense of physiognomy, and our use of the term, come from Joseph Church (1966) who talks of the young child, not yet able to read, who can tell one record from another on the basis of the groove patterns on the records. Physiognomic recognition is holistic and analogic. A striking example of this is the “strange friend phenomenon”. You encounter a friend and notice there is something strange about her, but you don't exactly know what. You scrutinize her and finally realize that, e.g. she changed her hair style. Or perhaps you don't figure out what changed and instead must be told. The initial recognition depended on a holistic, a physiognomic representation, not one which explicitly builds a full image from parts and parts of parts. If this initial recognition depended on a scheme which built the whole from the parts then there would be no trouble in discovering what had changed. The part would be found immediately. It is not, it takes time.
A scheme in which the whole is recognized as a composition over an arrangement of parts would be on the other side of the opposition, the propositional side (or digital, symbolic, sequential depending on your intellectual taste).
The reason I say Yevick’s version is the deepest is because she presents it in the context of a mathematical proof. She argues, in effect, that the world contains simple objects and complex ones. Simple objects are most efficiently and accurately recognized by a propositional method (to use the term Hays and I used), while complex objects are most efficiently and accurately recognized propositionally. Both are necessary.
I bring the matter up because the distinction is useful in understanding the sequence of biological conceptualizations we’re going to examine.
Rank 1: Ethnobiology and the problem of the unique beginner
Cognitive ethnologists have studied the ways in which preliterate peoples classify life forms [4, 5]. They find that in the regions where preliterate systems overlap modern taxonomy, they are agree on the structural relationships. But there is one anomaly. Preliterate cultures generally lack terms for what they call unique beginners. They’re have terms corresponding to our concepts of fish, snakes, birds, and beasts (i.e. four-legged fur-covered creatures with tails) and our concepts of tree, shrub, grass, and vine, but they lack terms for plant and animal, respectively. But, and this is important, they recognize the distinction between plants and animals by syntactic devices.
What does that mean? All animals can move under their own power; they can sense things (see, hear, smell, touch); they communicate through cries and calls. Plants don’t do any of those things. That means, for example, that animals can be subjects for verbs such as to run, to jump, to look, and to listen, but plants cannot. Similarly, both plants and animals can be subject for verbs such as to grow or to die, but inanimate objects (rocks, houses, bicycles, etc.) cannot. How is it possible to recognize systematic differences in the syntactic affordances of plants and animals without, however, having words to mark those two categories?
As far as I know, there is no accepted explanation for these observations. When I first read them I was incredulous, like Cowen is about the apparent lateness of a variety of ideas. The difference between plants and animals is obvious, no? Well no, not if we accept the ethnographic evidence. As I had no reason to doubt the evidence I was forced to come up with some explanation, if only to satisfy myself.
Here’s what I came up with. The ethnologists have also noted that ethnobiological classifications seem to be based on visual appearance. If we are willing to assume that basic visual classification is based on a physiognomic mechanism, then we can think of it like this:
Creatures having similar appearances are classified together. While fish, for example can be quite different from one another in appearance, any given fish will resemble another fish more than any fish resembles a bird, a snake or a beast. Similarly, any tree will resemble another tree (trunk below, roots in the ground, a large leafy structure above), more than any tree resembles a shrub (shrubs are smaller and the trunk is not nearly so distinct), a grass, or a vine. But what visual comparisons would force arbitrary examples of animals together in one class in distinction to arbitrary examples of plants in a contrasting class? Does it make sense to compare rats with trees, and trout with vines for classification purposes? Do trout and rats resemble one another more than either resembles a pine tree? Those comparisons don’t make sense. They’re distinctly odd.
Fortunately we don’t have to assume that physiognomic perception is basic. There is some evidence on the matter. Back in the 1970s Eleanor Rosch and her colleagues published a very influential series of studies that demonstrated that basic categorization seems to be organized around continuous gradation centered on prototypes as the best example of a category [6]. They concluded:
Segmentation of experience occurs to form basic levels which maximize the differentiability of categories. For categories of concrete objects, basic objects are the most general classes at which attributes are predictable, objects of the class are used in the same way, objects can be readily identified by shape, and at which classes can be imaged. Basic objects should generally be the most useful level of classification. Universally, basic object categories should be the basic classifications made during perception, the first learned and first named by children, and the most codable, most coded, and most necessary in the language of any people.
Assuming for the sake of argument that my speculative suggestion is on the right track we must now ask ourselves: How is it that syntax adequately differentiates between plants, all plants, and animals, all animals? How is it that the categories can be explicitly recognized in one context, but not other? Because the two contexts require very different cognitive acts. Classification involves the direct comparison of life forms. That’s very different from mentioning a plant or an animal in a sentence, which doesn’t require comparing life forms with one another. It only requires assigning the correct role with respect to some verb.
Once people can write things down, they begin to make lists, lists of any and everything. Now you are in a position to apply symbolic methods, propositional methods, to the objects that you had previously classified on the basis of a visual gestalt, a physiognomy. Classification can be extended. Once you do that you are in a position to notice that plants and animals are given systematically different linguistic treatment. Noticing those differences coaxes those categories into view where they can be explicitly named.
Rank 2: The Great Chain of Being
With Rank 2 we’re dealing with literacy, at least among a small elite. As I’ve already indicated, this elite makes lists, lists of everything; they pore through them, comparing, contrasting, reorganizing. That’s how they were recognize that trees of all kinds, shrubs and bushes, grasses and vines, that they all share certain characteristics. They sprout, they grow and mature, and die. The interesting thing about fish, birds, insects, snakes, and beasts, is that they do all those things as well (though they’re born or hatched instead of sprouting), but they do other things as well. They move, they see, hear, and smell, none of which plants do. And then we have humans, who possess all the characteristics of plants and animals, plus others as well. Additionally, humans talk and reason.
We are now in the domain of verbal elaboration. Physiognomic visual recognition and comparison have become eclipsed by verbally regulated comparison and inference. Using the capacity for metalingual definition that is characteristic of Rank 2 thought new concepts were defined and organized into a system. Philosophy was born, but not as the specialized academic discipline that it is today, but as a general mode of inquiry.
That’s what the Greeks did in the fourth and fifth centuries BCE. In particular, Aristotle Developed a conception that reverberated through Western culture will into the Middle Ages and beyond. The text I’m most familiar with is De Anima, (On the Soul), though the ideas are in other texts as well. The following account is somewhat simplified and abstracted but not, for our immediate purposes, misleading.
Physical things consist of a form and a substance. The form of a plant is a vegetative soul, which is responsible for reproduction and growth. To this animals add a sensitive soul, which supports mobility and sensation. In addition to a vegetative soul and a sensitive soul, humans also possess a rational soul, which is responsible for thought and reflection.
Consider these two paragraphs from a dialog I recently had with Claude:
What's philosophically elegant about this is that it's not a sharp discontinuity between levels but a nested hierarchy — you don't leave plant-soul behind when you become animal, you add to it. Every human being is still running the nutritive and sensitive functions; rationality is the additional capacity that crowns the sequence. That nested structure is what makes it so generative as a framework — it can absorb new observations without collapsing.
Then the Neoplatonists, particularly Plotinus, take this Aristotelian hierarchy and extend it upward — beyond human rationality to nous, the divine intellect, and then to the One, which is beyond all predication. So the chain gets lengthened in both directions — downward into matter and upward into pure being. And this Neoplatonic elaboration is what the early Christian theologians, particularly Augustine and then later the medieval synthesis, fuse with the Hebrew tradition's divine council and angelology.
That is to say, later thinkers appended a whole raft of animate creatures to this basic core, thus extending it to a trope that has become known as the Great Chain of Being, with minerals at the bottom, God at the top and a host of cherubs, angels, archangels and such between humans and God. This trope has been one of the central organizing concepts of Western thought, as Arthur O. Lovejoy demonstrated in his classic account, The Great Chain of Being: A Study of the History of an Idea (1936). When we move to Rank 3 the supernatural part of the chain will be cut free while the animate portion will gradually develop into the science of biology.
Rank 3: Learning to attend to the world
Hays and I introduced Rank 3 thinking in the cognitive evolution paper under the heading, “Subject and Object.” We then launch into a discussion of algorithmic calculation.
These procedures are so familiar to us, and so obviously elementary, that we forget that their creation was a major cultural achievement—attempting long division in Roman numerals, however, should remind us of just how very difficult computation can be without a good system of notation. Nor did the ancients have explicit rules of procedure. Marrou, in describing education in the Hellenistic period, writes
Strange though it may seem at first, it is nevertheless quite clear that addition, subtraction, multiplication and division ... were, in antiquity, far beyond the horizon of any primary school. The widespread use of calculating-tables and counting-machines shows that not many people could add up--and this goes on being true to a much later date, even in educated circles. (1956: 158)
In an additional note (p. 410), Marrou remarks that adults would often write out multiplication tables for themselves, presumably because they could not obtain answers out of their heads. Without a good system of notation the formulation of algorithms is so difficult that a complete set wasn't created for any number system other than the Indo-Arabic. Before these procedures were gathered and codified the calculations our children routinely make required the full attention of educated adults, who solved them on a case-by-case basis.
Thus prior to the introduction of explicit procedures (algorithms) arithmetic calculation was a chancy business, not so reliable as it is today.
Now we can think about how it contributes to clarifying the distinction between subject and object:
The world of algorithmic calculations is the same for all arithmeticians and is therefore essentially distinct from them. It is a self-contained universe of objects (numbers) and processes (the algorithms). The stage is now set for experimental science. Science presents us with a mechanistic world and adopts the experimental test as its way of maintaining objectivity. A theory is true if its conceptual mechanism (its "algorithm") suggests observations which are subsequently confirmed by different observers. Just as the results of calculation can be checked, so can theories.
In this respect, theory differs from definition. The test of a definition is that it suffices for the cognitive process of rationalization. The thinker explores a network of definitions, from charity to reward, from reward to the abstractions needed in defining it, and so on step by step. If this expansion leads to a sense of satisfaction, perhaps specifically a sense of coherence, then the thinker accepts the new definition, and claims to know what charity is. The thinker may also be able to decide whether a specific incident is an act of charity. But the process of exploration is not under the overt control of the thinker—it is meditation, not calculation. The thinker who has an algorithm does not enact it or meditate on it, but executes it. From this difference in process follows the fact that theories can be checked—the observations and calculations of different workers can be compared—but not definitions.
Definitions need only contribute to a coherent system of thought. The medieval world of the Great Chain, from minerals, through plants, animals, and humans and then to angels and finally to God, at the top, that was wonderfully coherent. But visual verification beyond humans was difficult.
And since Cowen introduced Renaissance painting as one of his pinnacles, let’s take a quick look at that. Consider these remarks that Claude made in a dialog I had about the prerequisites of Linnaean classification:
The medieval schematic image — the flat, hierarchically scaled, symbolically organized religious painting — wasn't trying to show you what things look like. It was showing you what things mean, their spiritual significance, their place in a divinely ordered cosmos. Scale indicates importance, not spatial position. A saint is larger than a peasant because sanctity outranks peasantry, not because the saint is closer to the viewer. The image is organized by conceptual and theological logic, not by the logic of how light falls on surfaces and how the eye receives it.
Linear perspective imposes a completely different organizing principle: the image should represent what a viewer standing at a particular point in space would actually see. This requires treating the visual field as something that can be systematically analyzed — rays of light, vanishing points, the geometry of foreshortening. Brunelleschi's famous demonstration in Florence in the 1420s treated perspective as something that could be proven, almost in the mathematical sense. Alberti then codified it as a system that could be learned and applied. It becomes, in the relevant sense, an algorithm for picture-making.
The parallel with the botanical question is exact. In both cases the shift is from representation organized by conceptual authority — the theological hierarchy, the ancient text — to representation organized by fidelity to direct observation. And in both cases the shift requires developing new technical methods for achieving that fidelity: perspective geometry for the painter, systematic verbal description and herbarium specimens for the naturalist. The new standard of accuracy creates the demand for the new tools.
There's also a social and institutional parallel. Realistic pictorial representation, like systematic natural history, required a community of practitioners developing shared standards — what counts as a successful rendering of foreshortening, what counts as an adequate botanical description. Both communities were forming in roughly the same Italian and northern European milieu, in the 15th and 16th centuries, often with the same patrons and in the same cities. The detailed botanical illustration that became essential to natural history — think of the great herbals of the 16th century — required both traditions simultaneously: the naturalist's eye for identifying and describing the plant, and the artist's training in realistic representation to render it accurately enough to be taxonomically useful.
Dürer is the figure who perhaps best embodies the confluence. His watercolors of plants and animals — the Young Hare, the Great Piece of Turf — are simultaneously works of art and works of natural observation of a quality that had no real precedent. He was applying the new pictorial technology of realistic representation to the natural world with an attentiveness that anticipates the naturalist's sensibility. Whether or not he thought of himself as doing natural history, he was developing exactly the kind of cultivated visual attention to particular organisms that Linnaeus and Darwin would later bring to the field.
Dürer’s skill in making images of plants and animals didn’t just happen. It came about through a historical process, one which Ernst Gombrich has discussed in some detail in his magisterial Art and Illusion: A Study in the Psychology of Pictorial Representation (1960). Gombrich starts with the ancient world and works his way through the Middle Ages, the Renaissance and through the Nineteenth Century, explaining the multiplicity of specific techniques, which he calls schemas, that artists had to develop in order to solve a multiplicity of problem in visual representation.
Until these techniques had been developed and rendered routine, the naturalistic depiction upon which Linnaeus, Darwin and others dependent would have been impossible. It’s one thing to look and to observe. It’s something else to be able to make a permanent record of one’s observations. Without that record the descriptive biology (natural history) of the 15th through 19th centuries would have been impossible.
Now we are ready to follow Cowen’s discussion of Linnaeus.
Linnaean classification
Before getting to Cowen’s discussion of Linnaean classification (pp. 65-70) we need to take a look at the conceptual and physical infrastructure on which Linnaeus built his system. That starts in the late 15th century. According to Brian Ogilvie, The Science of Describing: Natural History in Renaissance Europe (pp. 30 ff.), that’s when thinkers began investigating a simple question: Are the flora and fauna described by the ancients the same as those around and about us today? That question presupposes the conceptual reorientation we’ve just discussed, from doctrinal conformity to empirical observation. That question, in turn, led to questions of a similar kind: When I send word to Paris, how will they be able to tell whether or not the flower I’m describing here in Florence exists there? Such questions prompted the development of standards for describing and drawing flora and fauna and for developing reference collections of specimens.
Here I want to emphasize the importance of drawings and reference collections. Plants and animals are complex physical objects. Language is not a good medium for describing them. They’ve got many attributes, complex shapes with many parts, various colors and textures. It would be possible to describe something for several paragraphs without, however, creating an account that would allow a naïve reader to recognize the thing when they saw it. Drawings are much more useful – think of those drawings that Albrecht Dürer made of plants and animals. But reference specimens are the most useful of all. Those reference specimens become museums of natural history.
This takes us back to the distinction we made at the beginning of this discussion, the distinction between physiognomic and propositional modes of perception and cognition. Rank 1 classification of flora and fauna was based on physiognomic perception alone and so was unable to produce words for plants and animals as general categories. Rank 2 was able to do that by specifically attending to the linguistic record, where the similarities among plants on the one hand and animals on other became manifest in syntactic patterns, patterns available for inspection in a way impossible for speech, which in effect would not “stand still” for inspection. The Rank 3 regime of naturalistic observation and classification make use of both cognitive modes.
This more effective descriptive apparatus emerged during over a period of several centuries, resulting in a considerable international intellectual ecosystem that supported the study and classification of life forms. Linnaeus had that ecosystem at his disposal, as did Darwin a century later. Without it, their work would have been impossible.
Given the amount of time needed to create that ecosystem, just how early would it have been possible for Linnaeus to develop his system of classification? Life forms are very complex objects having many identifiable features on which a classification system can be base. It’s one thing to have a robust system for identifying them. Classifying them is something else. Which among the many characteristics of a life form should be used as the basis for classification? What are the criteria for selecting them? That’s a tricky question.
Years ago I faced it directly. I was bibliographer for what was then the American Journal of Computational Linguistics (now just Computational Linguistics). I had to prepare abstracts for the quarterly issues and that involved placing each abstract in the journal’s taxonomic tree. Each article had various characteristics on which classification could be based: Was it about pragmatics, semantics, syntax, or phonology? Was it formal or computational, perhaps both? If computational, which computational system? Perhaps it was cognitive psychology relevant to computational issues. Figuring out the best slot in the taxonomy was often difficult. What’s worse, as more articles entered the system, the system itself had to change. And the system I was dealing with was far smaller than the one that confronted Linnaeus.
I would have been happier if Cowen had come out and said: Taxonomy is difficult. Well, he does say that, but, as we’re already seen, not before he’s invited us to think it is simple: “They should have mastered this in the Dark Ages!” Of course, he wrote that with a touch of irony; he doesn’t want us to believe it, not quite. For a sentence later he tells us: “But no, taxonomic botany was difficult to figure out.” Why the rhetorical bait and switch? It’s as though he doesn’t quite believe that it really is difficult but the historical record testifies to the difficulty, so, well, that’s what he has to report. That is, he understands the difficulty from the outside, from what he’s been told, not because he understands and has wrestled with the nature of the task. Based on his own experience, taxonomy is something that should have been mastered in the Dark Ages.
Cowen notes (p. 66):
Earlier, there had been so many different classificatory schemes, sometimes based on plant shapes, habitats, or perhaps by the medical or agricultural uses of the plants. But those systems were not typically consistent across different nations or environments, for instance as a particular plant would be used differently in varying locales. These earlier classificatory schemes often lacked universality, and they had too many conflicting organizational principles. The Linnaean system, in contrast, focused on sex, stamen, and pistils.
He then goes on to note the difficulties that John Ray had in creating a system, creating a system that (p. 67) “was too cumbersome and too difficult to replicate or teach. It was never clear which was the exact rule to apply.”
As Cowen has indicated, Linnaeus’s key insight was to base his classification the plant’s sexual organs, stamens and pistils. That puts a somewhat fuzzy lower bound on when Linnaeus could have come up with the system as (p. 66) “It was not until the late 17th century that European naturalists generally recognized that plants engaged in sexual reproduction at all.” Thus Linnaeus’s system couldn’t have happened before the late 17th century.
But, I’m curious? Just when in the late 17th century? So I issued a Google query: “When did botanists learn that plants reproduce sexually?” The AI Overview gave me three dates:
- 1694 (Discovery): Camerarius demonstrated experimentally that the stamen was the male reproductive organ (producing pollen) and the pistil was the female organ. He proved that viable seeds could not be produced without pollen reaching the pistil.
- 1735 (Popularization): Swedish botanist Carolus Linnaeus popularized the sexual system, organizing plant taxonomy entirely around the number and arrangement of their male and female reproductive structures.
- 1851 (Universal proof): Early ideas only focused on flowering plants. It wasn't until 1851 that German botanist Wilhelm Hofmeister mapped the life cycles of non-flowering plants (like ferns and mosses), proving that sexual reproduction and the alternation of generations occur universally throughout the plant kingdom.
So Linnaeus was in fact ahead of the curve. Interesting. The larger point, however, is that there is nothing self-evident about the sexual nature of plant reproduction and that it took a century and a half of observation and experimentation to nail it down.
Frankly, in view of these considerations – mastering visual representation, propagating descriptive materials through continent-wide networks of researchers, amassing repositories of descriptive and reference material from around the world, the difficulty of proving that plants reproduced sexually – Cowen’s judgment that botanical classification is a “laggard science” seems rather willful to me. Or perhaps he’s telling us that the whole cascade of enterprises was laggard, not just the classification process, as though if only people had been on the ball it would have been completed in Aristotle’s time, or at any rate, by the time Shakespeare had written Romeo and Juliet.
Let’s see how he handles Darwin.
Rank 4: Theory of Evolution
Before Cowen gets to Darwin and evolution, he covers geology, another laggard (p. 70): “Some of the most important ideas became apparent only in the 18th century, even though they were available for clear viewing throughout the entire history of mankind.” He notes that the big advances (p. 70) “were fundamentally conceptual in nature.” And so (pp. 70-71):
One key shift in thinking was the move from seeing the Earth as young in age and relatively static, to thinking of geologic time as an important matter in its own right, rife with information about the development of life as well. The time scale had to be enlarged greatly, and to be seen as involving change, lots of information, and full of lessons for the history of mankind on earth.
From today’s vantage point that all sounds trivial, and I recall that I, like many other young children, had some of my earliest scientific fascinations with fossils and most of all dinosaurs. I loved going to the Natural History Museum, and reading dinosaur books, and I recall it all seeming so intuitive to me. I think I was seven or eight years old, and I grasped the (very basic) fundamentals of geology without much hesitation.
Yes, the diamonds-water paradox seemed trivial to Cowen when he was thirteen (p. 13), sometime after he’d mastered the fundamentals of geology.
Since I’ve already quoted Cowen on this several times, it seems a bit silly to do so one more time, but I can’t resist: “This heightens the puzzle. Like the basic laws of economics, many of the most basic insights from ‘geology as a whole’ just do not seem that difficult. It is strange that it took many centuries for the very smartest humans to figure out those truths.” It’s as though the smartest humans should have been able to figure everything out not long after Adam and Eve had been expelled from the Garden of Eden, or, at any rate, no more than three of four decades after fire had been mastered.
But I digress. Just before he transits to evolution, Cowen observes (p. 75-76):
As usual, you can find anticipatory figures who came before Hutton, Lyell, and their important geologic peers. Yet the scientific world as a whole could not digest the relevance of those observations. People just didn’t have the conceptual frameworks to put the whole picture together, nor the sustained scientific networks for the better observations to displace the errors and serve as building blocks for further progress.
There’s my point, right there, the conceptual frameworks.
Creating, testing, correcting revising, and evolving conceptual frameworks takes time, decades and centuries, even millennia. That’s what the cognitive ranks framework is about, the long-term evolution of conceptual frameworks, where each rank is conceptualized as the emergence and consolidation of, in effect, a meta-framework, speech, writing, calculation, and computation successively. Despite the fact that Cowen as explicitly acknowledge the importance of conceptual frameworks, he doesn’t seem to have a way of taking them seriously, not in a sustained argument. Every time he tells us that this or what seems obvious he’s contradicting the importance of those same conceptual frameworks. Cowen doesn’t have tools for thinking about thought, but he doesn’t seem to know that he doesn’t know.
Evolution affords us an opportunity to think about one aspect of conceptual frameworks, their capacity for conceptualizing identity. The formulation of an account of biological evolution depends in part on solving a problem having to do with identity. Cowen doesn’t mention the problem, but he comes close. On page 79 Cowen tells us: “Lyell himself was skeptical about the idea of the mutation of animals, partly for theological reasons, so what influenced Darwin was his geology, not any biological insight per se.” Those theological reasons had to do with identity.
Presumably Lyell would have believed in the independent origin of each species. As Claude remarked to me in a recent dialog:
The doctrine of special creation — the independent origin of each species — had a specific intellectual function: it guaranteed that species were real, stable, natural kinds. Each species was a fixed type, created with its own essential nature, and the task of the naturalist was to identify and classify these fixed types. This is Linnaean natural history in its metaphysical foundation — the classification system works because the categories it employs correspond to real, stable, independently constituted entities in nature.
Transmutation threatened this foundation at its root. If species can transform into other species, then species are not fixed natural kinds but temporary configurations in a continuous process — which raises the uncomfortable question of whether they're real in the way that classification assumes. Lyell understood this clearly.
These days we are so very used to the idea of biological evolution that we aren’t sufficiently alive to the fact that there is a real conceptual problem here. The theological problem is deeper than mere fidelity to an ancient story. It rests on a real conceptual problem: “mutation” of animals requires that we maintain some kind of continuous identity through different morphologies along the whole phylogenetic chain. They are different things, yet in some sense they are also the same. Is this some kind of intellectual parlor trick? What is the basis of that identity?
The problem is similar to, but deeper than, the riddle that the Sphinx poses in the story of Oedipus: “What is it that goes by four legs in the morning, two in the afternoon, and three in the evening?” We are asked to find an identity that encompasses those three different images, those three morphologies. The answer is man, “who crawls on all fours early in life, walks upright for most of his life, but then uses a cane in old age.” That continuity is something that we have observed directly. It is not puzzling.
The mutation of animals problem is similar in kind but more difficult. Why? Because we cannot observe the continuity directly; in a sense, the continuity is something of an illusion. The different life forms really are different. As Claude remarked in that same dialog:
The continuity cannot be experienced. It must be inferred from indirect evidence — fossil sequences, comparative anatomy, geographical distribution, embryological similarities. And crucially, as you say, the continuity is in a sense constructed rather than discovered: the different life forms really are different. There is no continuous individual whose development you're tracking. The identity across the phylogenetic chain is a theoretical posit — a kind of object that didn't exist in natural history's conceptual vocabulary before Darwin.
Now we’re in a position to see why Darwin is a Rank 4 thinker while Linnaeus is Rank 3. Again, Claude:
Linnaean classification is Rank 3 because it takes organisms as objects and applies systematic descriptive technique to organize them — metalingual definition plus rigorous observation plus reference collections. The categories it employs — genus, species, family, order — are derived from the organisms' observable properties and organized by a consistent classificatory principle. The system is sophisticated and cumulative, but its objects are given directly: you can see the organism, examine the specimen, compare the illustrations.
Darwin's move is to take the classification system itself as object and ask: why does this system have the structure it does? Why do the nested hierarchies of Linnaean taxonomy — species within genera, genera within families, families within orders — fit together so neatly? The answer natural selection provides is that the nested hierarchy reflects genealogical descent — the categories aren't just organizationally convenient, they're causally real, corresponding to actual branching events in evolutionary history. The classification system, which Rank 3 thought with, becomes the primary datum that Rank 4 has to explain.
The mechanism Darwin posits — natural selection operating on heritable variation — is a control structure in exactly the sense relevant to Rank 4. It's not a description of what organisms are but a model of the process that generates the distribution of what organisms are. It takes the population, not the individual organism, as its primary object, and asks about the dynamics that govern the population's composition over time. This is the move from describing the state to modeling the mechanism — from Linnaeus's taxonomy of what exists to Darwin's theory of why what exists is distributed the way it is.
Here’s the key phrase: “a model of the process that generates the distribution of what organisms are.” It’s that model the justifies the continuous identity across the different species, as identified by their differing morphologies, in a phylogeny. And crucial parts of that model wouldn’t be discovered until well after Darwin had published – I’m thinking of Mendel’s experiments in the 1850s and 1860s, but which weren’t recognized until the early 20th century (Darwin didn’t read his work), and of Watson and Crick’s discovery of the structure of the DNA molecule in 1953.
So, yes, as Cowen asserted at the beginning of his treatment of evolution: “Theories of evolution and natural selection also are intuitive once you understand them, and they seem virtually inescapable once you are willing to consider them seriously” (p. 76). What he’s not telling us is that we’ve all been taking them seriously at least since high school biology class, if not before. We’re not confronting those ideas as new ones in an intellectual environment built on very different assumptions. We didn’t have to make the leap of intellectual faith that Darwin did. We had the assurances of our elders that, yes, these ideas are true.
What about lateness?
Cowen concludes the chapter with these observations (83-84):
By studying the slow intellectual development of economics, and contrasting it with other fields of study, we can learn the following:
1. Some insights are very hard to grasp, even if they are apparently simple once they are understood. People need to “see around corners” in the right way to understand these insights and incorporate them into their world views.
2. Economics is one of those fields, and that is why it took intuitive economic reasoning so long to evolve, marginalism included. Those of us who are educators, or who spend time talking to policymakers, should take this point very seriously.
3. Even very, very smart people are likely unaware that these “see around the corner” insights are missing – did Euclid rue that he did not have access to proper supply and demand and tax incidence theory? Probably not.
4. Economics is not the only such field that is hard to grasp, some other examples being segments of botany, geology, and evolutionary biology.
5. Scientific revolutions come about when many complementary pieces are in place, such as financial support, intellectual independence, and networks of like-minded others to talk with. Those conditions help people to understand that “seeing around those corners” can bring both high social and professional returns.
I agree with the first sentence of the fifth statement. But everything else depends on Cowen’s epistemic metaphor, “seeing around corners.” To be blunt, I find it empty.
In my previous post I discussed the fact that Cowen doesn’t mention Thomas Kuhn’s classic study, The Structure of Scientific Revolutions (1962), where he writes about going from one paradigm to another involves a Gestalt switch, a phenomenon well-studied in psychology. Kuhn’s use of it may be analogical, but it is principled and illuminating in a way that Cowen’s “seeing around corners” is not. Rather than recount that argument here, I urge you to read that post.
As for the idea that some ideas are late while others, presumably, are on time (or even early?), that depends on an assumption that there is a proper tempo for the unfolding ideas, but Cowen doesn’t justify that assumption in any way. All he does is point out that some pinnacles of human achievement happen earlier than others. That hardly justifies the conclusion that the more recent ones are lagging behind.
Though, come to think of it, this may be where those various statements of obviousness come in. Thus: Since evolution is obvious in retrospect, but Hamlet is not, evolution is late. Or perhaps: Since the basic truths of geology are obvious to a bright eight-year old but Plato’s allegory of the cave is not, geology is late. I’m not convinced.
Come to think of it, the argument in this chapter is dependent on our willingness to take Cowen’s various judgements at face value. I’ve been emphasizing those retrospect judgments of obviousness whether stated generally or indexed to his childhood. But those aren’t the only judgements in this chapter.
Consider this statement (p. 60): “If you consider Ptolemy, Kepler, Brahe, and Galileo, there were no contemporaneous economists of comparable import or quality.” Economics is so different from astronomy and physics that I don’t see why the comparison is relevant. There weren’t any exobiologists of comparable quality either, not to mention writers of science fiction or rock guitarists. Then we have Cowen’s assertion that “It is plausible to regard Shakespeare as the greatest author of all time, to this day” (p. 61). It is one thing to assert that he’s the greatest literary author the world has seen, but Cowen’s assertion is more general that. It’s comparable to a remark he made on his blog, Marginal Revolution, in June 2017: “Shakespeare is very likely the deepest thinker the human race has produced...” So he’s deeper than Plato, Newton, Hume, Darwin, and Einstein, among others. I find it had to believe Cowen asserted that, but the statement is there and the assertion in this monograph is consistent with it. On the other hand, he pulls his punch with Bach: “Perhaps Johann Sebastian Bach was the greatest and most musically complex composer of all time?” (p. 60). It’s not that I think some other composer deserves that honor. Rather, I don’t find the statement very meaningful. I don’t understand how such judgements can be made with any rigor. An argument that depends on our willingness to accept all of these judgements at face value is a precarious argument.
Finally, as Claude remarked in an earlier post, Cultural Evolution and (Tyler Cowen’s views on) History, Cowen lacks a robust approach to history:
Tyler uses history throughout the book but doesn't have a philosophy of history in any strong sense. His historical examples — the slow development of botanical classification, geology, the Marginal Revolution itself spreading unevenly across decades — are deployed instrumentally, to illustrate why intellectual progress is non-linear and contingent. [...] But he never steps back and asks what the overall shape of history is, whether it has direction, whether the peaks of creativity he identifies are connected by anything deeper than circumstance.
What you're left with is essentially a punctuated equilibrium model without the theory — bursts of insight separated by long plateaus, with the bursts explained by the convergence of multiple enabling conditions: the right institutions, the right communication infrastructure, the right social permission to think heterodox thoughts. [...] That's not nothing, but it's also not a philosophy of history. It's pattern recognition dressed as explanation.
References:
[1] William Benzon and David Hays, The Evolution of Cognition, Journal of Social and Biological Structures 13(4) 1990, pp. 297-320, https://www.academia.edu/243486/The_Evolution_of_Cognition.
[2] Holographic or fourier logic, Pattern Recognition, Volume 7, Issue 4, December 1975, Pages 197-213, https://doi.org/10.1016/0031-3203(75)90005-9.
[3] William Benzon and David Hays, Metaphor, Recognition, and Neural Process, American Journal of Semiotics, Vol 5. No. 1, 1987, https://www.academia.edu/238608/Metaphor_Recognition_and_Neural_Process.
[4] Brent Berlin, Dennis E. Breedlove and Peter H. Raven, General Principles of Classification and Nomenclature in Folk Biology, American Anthropologist, New Series, Vol. 75, No. 1 (Feb., 1973), pp. 214-242, https://www.jstor.org/stable/672350.
[5] Berlin, B (1973). Folk Systematics in Relation to Biological Classification and Nomenclature. Annual Review of Ecology and Systematics, 4(1), 259–271. doi:10.1146/annurev.es.04.110173.001355
[6] Eleanor Rosch, Carolyn B Mervis, Wayne D Gray, David M Johnson, Penny Boyes-Braem, Basic objects in natural categories, Cognitive Psychology, Vol. 8, No. 3, July 1976, pp. 382-439, doi: https://doi.org/10.1016/0010-0285(76)90013-X.
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