Work in Progress: From Planetary Classification to Naturalistic Ethics
Friday 19 August 2022
I have returned from Scotland, so this newsletter is once again the view from Oregon. Despite all the things that could have gone wrong, overall my travel arrangements came off as well as or better than is to be expected. I had some delays, and I had to accept some curtailments to my touring plan (mostly as a result of my age and my need to sleep), but I got there and back, I participated in the entirety of the NoRCEL conference, and I got some sightseeing in that took me to Edinburgh, Robert Burns’ birthplace, Inverary Castle, Carrick Castle, Rosslyn Chapel, Blackness Castle, and Linlithgow Palace.
I have mentioned previously that, as soon as I finish a presentation, I think of ways to improve it. Since completing my “Toward Universal Biology” presentation I have more-or-less converged on a proposed initial planetary classification that would involve three terms: composition, size, and insolation (or stellar flux). This would nicely reflect the spectral classification used for stars, but that isn’t my primary motive for a tripartite classification. What is needed is something really simple as a basis for observations, which is enough to make the distinctions that must be made, but without incorporating too much information.
Composition categories would be T for terrestrial, G for gaseous, and I for ice giants, perhaps with further classification letters to come as we rough out further generalizations based on planetary composition. For example, we might want to distinguish another classification for planets like Mercury that form within the soot line and so have all their polycyclic aromatic hydrocarbons burned away. Another challenge here would be moons: do we include them with planets, since they have been rounded by their own gravity (at least, many moons are spherical) and are insufficiently massive to undergo fusion in their cores (the geophysical definition of a planet), and, if so, do we need another classification for subsurface ocean world moons, which offer some of the best prospects for finding life (but which are now largely beyond our ability to detect at interstellar distances)?
Size is an obvious term for the classification, but how ought we to divide sizes up into a workable number of classifications that covers and distinguishes Earth twins, super Earths, mega-Earths, mini-Neptunes, and so on? Should our metric be Earth masses or Jovian masses? How many taxa do we need? Probably we would not want more than ten taxa, but how it will be best to divide sizes into meaningful measures that reflect our intuitions will require a little work — but, still, this sort of thing is eminently doable and does not require any great flash of inspiration. It is merely a matter of putting in the work and reading enough papers.
Insolation or irradiance is a great measure because it combines planetary size, stellar energy output, and planetary distance from the star, so we get several relevant measures wrapped up in one number. We could express stellar flux in terms of some fundamental energy measure, or as Earth insolation equivalents. Whatever metric we employ, we have to break this continuum into categories, just as with size, and this poses similar problems as with size categories. There are problems here as well. Stellar energy might be predominantly in the visible spectrum (like the sun), or in the infrared, or in radio frequencies (pulsars), and this is an important distinction. An energy gradient in these different EM spectra might drive distinct physical processes on the planets in their neighborhood. Perhaps a subscript or subtypes could be introduced to account for this. I’m not sure yet how best to approach this.
Although what I have outlined is very rough, I think if I included this in a future iteration of this presentation (if any) it would give the audience a better idea of what I mean by an “initial planetary classification” that is distinct from any astrobiological classification (like distinguishing planets as to whether they are inhabitable or not habitable), and distinct also from my proposed exoplanet chemospheric seriations. We need an initial non-astrobiological system of classification in order to compare apples to apples and oranges to oranges, without pre-judging habitability, even though we are likely to focus on those worlds (planets and moons both) that are something like Earth twins in terms of the conditions for life (as we know it) that they afford.
Even though we would likely focus on Earth-like worlds, I believe that the research program into chemospheric seriation should be equally pursued in relation to gas giants and ice giants. For one thing, planetary systems on the whole, with their elemental, isotopic, mineral, and gas abundances, form the astrobiological context of life on Earth, as well as life elsewhere in the solar system. If it should turn out that there is life in the subsurface oceans of Enceladus or Europa or other gas giant moons, then this life, like Earth life, has the entirety of the planetary system as its astrobiological context that supplied these worlds with the resources and the conditions necessary for abiogenesis.
For another thing, we cannot (or should not) exclude the possibility or life, or life-peer chemical complexity, in the atmospheres of gas giants and ice giants. We can recall here Carl Sagan’s world of hunters, floaters, and sinkers in the Jovian atmosphere. which would occur in what we would today call and aerial habitable zone (AHZ). Whether or not this has occurred in the upper atmosphere of Jupiter, it might have occurred on some other Jupiter twin, perhaps in the atmosphere of a gas giant of a different size, of somewhat different composition, or a different distance from its parent star. It might take significant work to figure out the biochemistry of the life, but the seriation of gas giant and ice giant atmospheres would give us the parameters within which such life would exist. If, at a given age of a planet of a given type, we find a dependable transition in the atmosphere that indicates that something more is going on than abiotic chemistry, then that could be an origins of life transition.
Working on this presentation, as well as re-writing my previous NoRCEL presentation, “How many branches are there on the tree of life?” for a different group this coming November, has kept me focused on issues that might be characterized as the philosophy of biology, or the philosophy of astrobiology, but now I must pivot a bit. In September I am scheduled to be on a space ethics panel for SESA (Space Education and Strategic Applications — SESA 2022 Conference). The special session, organized by Michelle Hanlon of For All Moonkind, will be titled “Space Ethics — Addressing the Burden of the Highway Planner.” The reference to the highway planner comes from a quote from Peter Fleming that I shared with Michelle, “The highway planner needs to approach his tasks in a prayerful attitude. He is building not only for the present but for the long future, and thereby helping to shape civilization.” I, in turn, found this quote in Earl Swift’s book about the superhighway system. In any case, it is a great way to summarize the idea of planning for the human future in space, and it raises the question of what a prayerful attitude is when approaching something as nuts-and-bolts as constructing the machinery and the infrastructure that will get us into space. Some years ago I wrote a Centauri Dreams post, How We Get There Matters, which is pretty much the same idea; infrastructure shapes the society that builds it.
Also on the space ethics front, I am scheduled to moderate a track on space ethics for the Space Education Symposium this coming November, being organized by Mark Wagner and Annahita Nezami, both of whom are known to me through the Overview Round Table. Hence my need to shift gears from philosophy of astrobiology to ethics. However, there is some overlap, and in the final days of my trip to Scotland I started taking notes on some of these areas of overlap.
Regular readers will know that I have an interest in evolutionary psychology, and our moral psychology is closely intertwined with our evolutionary psychology. We are, first and foremost, biological beings, and our biology enmeshes us in a biological continuum in which other biological beings are equally enmeshed, and with which we therefore share not only the sinews of our bodies, but also much of the constitution of our minds. With this in mind, I have been thinking about the naturalistic tradition in ethics, which does not have the status of, say, utilitarianism in relation to teleology or Kantianism in relation to deontology, but really ought to have a more significant stature in our age of almost unquestioned naturalism as the conceptual framework for contemporary philosophy.
In classical antiquity we can cite as naturalistic ethicists Aristotle, Epicurus, Lucretius, and, I think, even the Stoics. While the Stoics often employed non-naturalistic rhetoric, Stoic ethics are no more supernaturalistic than are Epicurean ethics. There are some writings on moral psychology from the Scholastic period that might bear upon naturalistic ethics, but with the advent of modernity we have Hume standing at the beginning of a modern tradition of naturalistic ethics that culminates in Nietzsche. Nietzsche’s influence at the present time is so profound that one might not even think of him as a representative of naturalistic ethics, given his impact on so many areas of thought.
A thought experiment that shows the relationship between biology and ethics can be formulated as such: imagine a universe much like ours, but in which no life had arisen: no life, no sensation, no consciousness, no intelligence, etc. What value would such a universe have? What has been of decisive influence on me in this context is G. E. Moore’s test of intrinsic value, which is called “the method of absolute isolation,” and which is present implicitly throughout his short book, Ethics, but is given explicit exposition in his Principia Ethica:
“The method which I employed in order to shew that pleasure itself was not the sole good, was that of considering what value we should attach to it, if it existed in absolute isolation, stripped of all its usual accompaniments. And this is, in fact, the only method that can be safely used, when we wish to discover what degree of value a thing has in itself.” (G. E. Moore, Principia Ethica, section 53)
According to G. E. Moore’s test of intrinsic value we might find much in a universe empty of life to have intrinsic value if taken in isolation. However, if we add life to this sterile universe we have another thing that might have intrinsic value. And as life develops sensation, consciousness, and cognition, the universe through life is reflected on itself, and the forms of value (or potential value) multiply exponentially. This is an idea that I have been working on in one form or another for many years, and which was the basis of my first presentation at the 2011 100YSS, The Moral Imperative of Human Spaceflight. In this presentation I argued (in what I call my axiological argument) that universes with a greater number of values, with a greater number of kinds of value, and the ability to continue to produce new values, are to preferred over universes that are relatively impoverished in values on these measures. This can also be called a quantitative axiology.
What I have written thus far seems to put me entirely in the corner of axiological ethics, and my use of Moore could well be seen as a problem in this context, since part of Moore’s Principia Ethica is famous for its critique of naturalistic ethics, which has bequeathed to popular culture the idea of the naturalistic fallacy, which one can find discussed on Youtube channels. But I’m not going to put myself in a box like that, and I’m also not going to do a foundational inquiry at this point, because I want to use the tools that I have to extrapolate conventional ideas in ethics to a space ethics context. And another profound influence on my thought that is to be found at the intersection of biology and ethics is this quote from Darwin:
“The following proposition seems to me in a high degree probable — namely, that any animal whatever, endowed with well-marked social instincts, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well developed, or nearly as well developed, as in man.” (Charles Darwin, The Descent of Man, 1871, Chapter 4)
This idea is so fundamental to my conception of naturalistic ethics, and is so rich in implications that still have yet to be drawn out, that I cannot emphasize this passage enough. Darwin’s posthumously published notebooks are filled with similar observations on human moral development in relation to other animals that similarly cry out for further development. Darwin’s evolutionary view of humanity showed him the continuity of humanity with the rest of the animal kingdom. Darwin wrote in his notebooks, “Seeing a dog & horse & man yawn, makes me feel how ‹much› all animals ‹are› built on one structure.” And our minds are built on the same structure too. If we take the critique of the blank slate in an appropriately radical sense, we come to evolutionary psychology and the commonalities of the human mind with other minds in the biosphere.
At this stage in my thinking on space ethics my approach is highly eclectic, and I am just jotting down ideas that I hope may prove to be useful, even if I do not yet know how, when, or why they will be useful. I have learned from my interview on space ethics earlier this year, and my participation in the ethics proto-task force for the human space program, that most people do not view ethical discussions through the lens of philosophical ethics, so I do not expect any discussion to take place in this kind of context, but I want to be able to interject telling instances from philosophical ethics in order to make a point in a way that is distinct from throwing out a rhetorical point — something that poses a wider question and suggests ethical horizons not yet explored, which might yet alter our conception of our humanity and our place in the universe. That’s the ideal, but I also know that the ideal is rarely realized in the fast pace of discussion.
One of the great challenges when it comes to ethics is how it bleeds over into religion, politics, emotion, and law. In a philosophical context these adjacent problems can be kept at a distance while the technical details of a moral theory are examined, but in any popular or semi-popular discussion you will get moral talking points that are really ways of talking about politics or religion at one remove. And that’s fine, but one must be ready for this. Hence the need to be eclectic in preparation, in order to take in a wide variety of viewpoints to be able to profitably reframe or redirect them into ethics proper, without making some statement about politics or religion that would immediately compromise the discussion.
Ultimately what I would like to see is the reformulation of traditional ethical theories in a cosmological context. Let me give a concrete naturalistic instance of this, albeit an instance with which I have little sympathy. The moral theory of emotivism could be easily transferable to some other species in some other biosphere by accounting for the different suite of emotions that might be experienced by a biological being with different sensory endowments and a mind evolved with these different sensory endowments. The principles of emotivism could be treated as a constant, while the content of emotion changes from biosphere to biosphere. Indeed, we can do this moral thought experiment in our own biosphere. It has been observed by dolphin researchers that parts of the brains of dolphins associated with emotion are more developed than in human beings, so dolphins may be able to experience emotions that we do not feel. Dolphin emotivism, then, would overlap with, but also diverge from, human emotivism. The bigger problem, or, rather, the bigger challenge, is when we have to integrate all the emotions from many different species into a single cosmological context.
Placing traditional ethical theories in a cosmological context could mean our human ethical considerations must be qualified by life elsewhere, by other forms of intelligence, or even by an otherwise sterile universe in which humanity stands alone in splendid isolation, and so on — the possibilities are literally endless in terms of what we may need to account for when we attempt to survey the universe entire. And a semi-popular way to make this point would be to suggest that the overview effect gives us the first visceral glimpse of our cosmological context, and the moral reflection that follows from the overview effect is our initiation into moral theory in a cosmological context.
