Tag Archives: philosophy of biology

A Bad Argument Against Same-Sex Marriage

I would have scarcely believed it possible, but a few short hours after teaching the naturalistic fallacy in my Philosophy of Biology class, I was exposed to an argument–from a professional philosopher–that, roughly, same-sex marriage is problematic because a) marriage is all about procreation and the raising of children and because b) evolution tell us that reproductive success is important, therefore: Gay marriage should be frowned upon. This resistance then, has nothing to do with religion, God, or the divine sanctification. Rather, it is the scientific thing to do: resist gay marriage because it is against evolutionary demands made on us as a species. This means that active disapproval of homosexuality–societal and legal discrimination for instance–is an expression of a biological instinct and should not be condemned as a moral failing.

The outlines of this argument should be familiar to most folks. It has been made time and again and despite having been spectacularly debunked, it rises again and again, like a zombie, or your favorite refusing-to-die cinematic ghoul.

What this argument attempts–and fails–to do is derive a proposition with normative import from a set of propositions that are purely descriptive. This–as David Hume pointed out a long time ago in his A Treatise of Human Nature–is an instance of the naturalistic fallacy, an attempt to bridge the is-ought gap:

In every system of morality, which I have hitherto met with, I have always remarked, that the author proceeds for some time in the ordinary ways of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when all of a sudden I am surprised to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, ’tis necessary that it should be observed and explained; and at the same time that a reason should be given; for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it.

This fallacy manifests itself in the current situation as follows. There are biological facts about us: We reproduce, we pass on our genes, various reproductive strategies are adopted, some work better than the others (in securing more offspring to whom we can pass on our genes). This much can be ascertained by observation and measurement. But what should  we do on noting these observations? The proponent of the argument noted above, wants to derive the following: Those reproductive strategies that work ‘better’ are ‘good’, and therefore should be encouraged, should be praised. The rest should be condemned. (Marriage, it will be noted, has been admitted as a successful reproductive strategy; this is a matter of empirical assessment and could well turn out to be false.)

But whence ‘better’, whence ‘good’? Why is ‘reproductive success’ a moral good to be sought? What is the source of that valuation and why is it allowed to override other values in the derivation above? Might we be allowed to admit other values in arriving at an alternative conclusion? Like, for instance, a more tolerant society is a ‘better’ society than one that isn’t? But then, we would be opening up a debate–conducted within some broad ethical and moral frameworks–on valuation, which is precisely what our protagonist didn’t want. He merely wanted the straightforward elevation of reproductive success to the preeminent moral value without further debate.

The tireless proponents of the so-called evolutionary arguments against same-sex marriage forget that efforts to read normative judgments off the historical workings out of the evolutionary process have as much difficulty in bridging the is-ought gap as any other species of argument. Calling upon biology here is not the scientifically sophisticated thing to do; it is merely to reveal one’s ignorance of the limitations of evolutionary explanation.

The Practice of Science According to Article Abstracts and Headers

Sometimes close reading of article headers can pay rich dividends. On Monday morning, my Philosophy of Biology class and I were slated to discuss a debate crucial to understanding adaptationist  paradigms: the role of bodyplan (Bauplan) constraints in restricting an organism’s  occupancy of possible points in developmental space, which complicates our understanding of the supposed ubiquity and optimific qualities of adaptation. This cluster of debates was kicked off by the Spandrels of San Marco controversy (which later morphed into the Gould-Dennett dustup).

For reading, I had assigned the original Gould-Lewontin article, “The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme“, and Chapter 10 of Dennett’s Darwin’s Dangerous Idea. The class discussion on Monday provided a very good example of how a crucial debate in science and the philosophy of science could be put into a broader context. I began the class by putting up on the projection screen, the first page of the G-L article (from the link above); in the seventy-five minutes of class, we did not get beyond a discussion of the title and the abstract; unpacking the meta-data of the article was extraordinarily useful.

As my students and I noted, this was a reproduced scholarly article, one originally published by a reputable source of scientific knowledge–The Royal Society of London; this led to a consideration of the relative  worth of different sources of scientific knowledge and the standards that might evolve for the publication and promulgation of scientific advances, and relatedly, to the role of copyright law in scientific settings. The fact that this article was now available on the Internet spoke to another set of criteria affecting its current availability. We noted that while author affiliations were not available, we could look them up to find out that in this case, the two scientists worked at a very reputable institution; furthermore, the order of the names at least indicated to us that they might have considered alphabetical ordering of their names as a way to brush past the issue of supposed priority in the authoring.

With this preliminary analysis out of the way, we looked at the abstract itself, whose opening lines establish it as the opening volley of a polemical battle that is sought to be engaged:

An adaptationist programme has dominated evolutionary thought in England and the United States during the past forty years. It is based on faith in the power of natural selection as an optimizing agent.

The first sentence clearly lays out the target of the argument to follow; the second provocatively uses the word ‘faith’ to establish what the authors take to be problematic about the target of their critique.

And then, we were off into a consideration of the article’s arguments as foreshadowed in the abstract. But importantly, we were no longer thinking about them in isolation from the larger, social and political setting of the science, the debates within it (and their rhetorical aspects). At the least, our little close reading of a piece of scientific knowledge had made clear many of the institutional features in a domain of scientific knowledge that underwrite and prop up its claims, and yes, its evolution over time.

Adaptation, Abstraction

This spring semester, teaching Philosophy of Biology–especially the Darwinian model of adaptation and environmental filtration– has reminded me of the philosophical subtleties of  ’abstract model’ and  ’abstraction’. More generally, it has reminded me  that philosophy of science achieves particularly sharp focus in the philosophy of biology, and that classroom discussions are edifying in crucial ways.

In its most general form, the Darwinian theory of adaptation by ‘natural selection’ states that adaptation results if:

There is reproduction with some inheritance of traits in the next generation.

In each generation, among the inherited traits there is always some variation.

The inherited variants differ in their fitness, in their adaptedness to the environment.

In teaching this version (taken from: Richard Lewontin, Adaptation. Scientific American.  239: 212-228 in Rosenberg and Shea’s Philosophy of Biology) I point out how much this concise statement of the theory leaves unspecified–the entity reproducing, ‘traits,’ the mechanisms of reproduction and inheritance, the sources of variance,  the nature of ‘fitness’, the extent of the environment, and the mechanisms and characteristics of the adaptation–even as it provides an explanatory framework of great power and scope. (This under-specification allows  the model’s statement too, in terms of interactors and replicators.)

The generality of the Darwinian specification reminds us of the practicing mathematician’s adage that the sparsest, barest definitions result in the richest, most interesting theorems. In this case, the theory works with a diversity of hereditary mechanisms and sources of variation, and does not require or imply any particular one. Rather, it merely requires that there be some  mechanism for heredity and some source of variation in heritable traits for every generation in every line of beings. I think it’s a fair bet to say that if there were any appreciative reactions in class to this discussion of the theory, they were grounded in a grasp of the theory’s generality.

Getting clear about the abstraction of the Darwinian model is crucial in understanding why it does not issue teleological explanations, why it cannot be understood as ‘progressive’, and why it is plausibly extensible to different levels of theoretical explanation in more than one domain of application. Later, our descriptions of  blind variation and selective retention as algorithmic processes enabled another reckoning with the abstraction of the model’s substrate neutrality. (Discussing this with my students reminded me of teaching the multiply-realizable computational model of the mind in classes on the philosophical foundations of artificial intelligence, especially as our discussion segued into an attempt to understand the abstract notion of computation.) In general, I sought to clarify why the model specified above is an ‘abstract’ one and what relationship its abstraction has to its generality and its explanatory scope.

Unsurprisingly, at moments in my exposition, I found myself rediscovering admiration at the theory’s Spartan outlines.  I was pleasantly surprised too, by how sophisticated my students’ interjections and questions became as they attempted to take on and apply the theory; they forced me to think on my feet in addressing them. More than anything else, their class responses reminded  me that a particularly important species of learning takes place in the course of teaching.

Nietzsche, Power, and Bible-readers on the Subway

Last evening, after a full day of work teaching Philosophy of Biology, a seminar on Nietzsche, and conducting a teaching observation of a graduate fellow, I left campus for my evening weightlifting session. I was feeling run down, and not a hundred percent. Perhaps it was the lack of sleep, perhaps a nagging cluster of cold-sore throat related symptoms that were insidiously undermining my ability to face up to the world. As I rode the subway to the gym, I felt uninspired and sleepy; the book I had intended to read only had a few of its pages turned.

Thankfully, the lifting went well. I was scheduled to back squat (Crossfit South Brooklyn is following the Wendler Cycle for our strength programming), and after lifting 185×5, and 205×5, I did my maximum-repetitions set at 230 (for 12 reps). By the end of it, my legs were shaking, I was close to hyperventilating, and a clarity-inducing  surge of euphoria had seemingly cleansed me of the sluggishness of the afternoon.

I changed, and made my way to the 7th Avenue subway station to head home. As I waited for the train, I pulled out my copy of Karl Jasper‘s Nietzsche: An Introduction to the Understanding of his Philosophical Activity (JHU Press, 1997) , and, somehow emboldened, began to read:

The pyschology of the feeling to power: Nietzsche’s conception of the ‘will to power’ is by no means identical with his conception of the drives that aim to provide a feeling of power. The one relates to genuine being that has become extra-empirical; the other to observable psychological experience. The one involves an abstract will, intent upon determining the course of its own being; the other, the conscious pursuit of the enjoyment attending the feeling of power.

I stared back at the page. Really, was this where I had left off, and now, resumed reading?

As I sat on the bench, a lady on her way back home sat down next to me and opened up a book. It was the Bible. She opened it to Numbers 25, and began reading. I sat there for a few seconds, and then, unable to resist, spoke: “Excuse me, are you reading the Bible straight through or picking selections?” The lady smiled, and said, “I’m reading it straight through.” I then asked, “Have you read the Bible before?” She smiled again, and said, “No, I’ve read it many times before.  This time my reading has been a bit slower; I got bogged down in Leviticus for a bit.” I nodded; sometimes I too, get mired in parts of books I read.

A B train pulled in and discharged its passengers, who swarmed around us to head for the exits, as we sat there with our books open on our laps. I wondered if my new acquaintance would ask me about what I was reading, and how I would describe it if she hadn’t heard of Nietzsche. She then spoke again, “Are you a believer?” I replied, “No, but I’m always curious about people that appear to be serious readers.” Her reply was made inaudible by the arrival of the Q train. I bade her take care as I headed for a subway car.

I wonder what Nietzsche would have thought about it all: a hundred years after his death, philosophy professors, on their way home after weightlifting, reading books about his writings, sitting next to readers of the Bible, all the while ensconced in the bowels of a gigantic subterranean transportation system in an American city.