Posted by: dacalu | 26 June 2016

Christian Change

Today, I was delighted to worship with the people of St. Margaret’s, Prestwich, just north of Manchester.  Here is the sermon I shared.



2 Kings 2:1-2, 6-14 (Elijah leaves Elisha behind)

Galatians 5:1,13-25 (“For freedom Christ has set us free”)

Luke 9:51-62 (“Foxes have holes, and birds of the air have nests; but the Son of Man has nowhere to lay his head.”)



Preaching is hard.
This week’s readings are full of teachings about freedom and belonging,
	holding fast and moving on,
	home and pilgrimage.
Jesus passes through a Samaritan town, 
	and they are willing to believe in his power,
	but not in his destination.
The Samaritans saw themselves as different,
	for they believed that God might be worshipped anywhere,
	and not just at the Temple in Jerusalem.
They accepted Jesus’ message of change,
	but wanted even more change.
	Jesus was bound to Jerusalem, 
and they would not accept this.
	And so they did not accept him.
And yet, Jesus tells his followers:
	“Foxes have holes, and birds of the air have nests; 
but the Son of Man has nowhere to lay his head.”
	They must be always traveling
		to follow God’s call.

And this week’s news is also full of talk about freedom and belonging,
	holding fast and moving on,
	home and pilgrimage.
Paul’s words as well as Jesus’ could be used to argue both sides of the Brexit issue.
	No doubt they have been used on both sides.
But I am from the US and I shall not, 
partially out of self-preservation, 
wade into the issue, 
other than to say this:
whether we are part of something or hold ourselves apart
is indeed a Christian issue,
perhaps even one of the deep mysteries of faith.
It is something worth praying about.
So this week, preaching is doubly hard.
	I am honored to feel at home in Manchester,
	But I am also a pilgrim.

Every year I come to Northern England for a retreat.
	I am a member of the Society of Ordained Scientists,
	a group of priests and deacons who are also trained in the sciences
		and invested in making the most of human wisdom
		wherever it may come from.
	My own background is in biology.
		I took my doctorate at Harvard University,
			studying the evolution of photosynthetic reactions centers,
			and I work with NASA on the search for life in the universe.
		That means I think a great deal about what it means
			to be at home in the universe,
			and what it means to travel.

One of the recent insights of biology has been to note the amazing diversity
	that is the human body.
Each of us is made up of trillions of cells.
	One half of those are genetically you.
	The other half are tiny organisms that live in your gut and on your skin.
	Those organisms help protect us from the environment,
		they help us digest our food,
		and they exist in a complex network of relationships with one another
		just as we exist in complex relationships with plants and animals.
It turns out that being human is more complicated than we thought, biologically.
What we thought was essential and sufficient – our DNA – is only part of the story.
	An important part, to be sure, but only part.
Humanity is more than we thought,
	and what we thought was our all in all,
	turns out to be only a part.
You may have been told you ARE your body,
	but that can mean many things.
Certainly we are made up of physical stuff,
	and I’m comfortable saying that I AM PHYSICAL.
	Still, that physical stuff comes in an amazing array
		of genetics, processes, and interactions.
	I exist in constant communication with my environment,
		as I take on new cells and new organisms,
		as other cells and organisms pass away.
	I am in the process of living.

When you are priest and a biologist you think about these things.
	You notice, for example, that bread and wine cannot be made 
without plants – wheat and grapes – 
without microorganisms – yeast and bacteria –
and without human action.
	And so we celebrate here, with bread and wine
		the amazing interconnectedness of creation.
	We should not be surprised that we, too,
		as individual people and as the church,
		are made up of diverse parts.

In Galatians, Paul encourages us to follow the freedom of Spirit,
	and not be slaves to our flesh.
I do not think he means us to deny our physicality,
	our particularity, our fleshliness.
Rather, I think he means we are to understand ourselves as flesh
	in process.
God is moving through us,
	so that through us
	flesh might become Spiritual.
We live by holding on to our physicality,
	to our specificity,
	to our place and time and customs,
	but only for so long.
My flesh, which I must care for if I want to live now,
	I must shed if I wish to live forever.
I must take on new flesh,
	just as I eat food to make new cells,
	and new tissues;
	just as I take on new habits.

Jesus calls on the Samaritans to change, and turn toward Jerusalem,
	just as he will invite the Sadducees to turn from the Temple
		and invite the Pharisees to turn from the Law,
		so that they may find God in him.
This is the peace that is no peace,
	our constant pilgrimage
	from where we are to where God calls us to be.
We must not pin ourselves in place,
	so we cannot follow where Jesus leads.

I hope you don’t take me to be too progressive.
	Truly, I am not.
Sometimes we must hold fast.
Sometimes we must set our face towards Jerusalem.

To what, then, do I hold fast?
	I hold fast to God – not as an abstract idea, but as a concrete person
		for some, like myself, it is easiest to talk to God as Creator 
and Governor of the cosmos
		for others, it is easiest to talk to Jesus Christ, the man
		for still others, the Spirit of God speaks in sighs too deep for words
		but all of us hold fast to a personal relationship with God.
	I hold fast to you – not as an abstract church, but as concrete neighbors,
		transitory and confused, just as I am transitory and confused
			by the changes of life
		and yet taking joy in the relationships,
		in discovering God in you and discovering more about myself
			every time I see myself as I am with others.
	I hold fast to the coming kingdom,
		both the hope of a home beyond this passing world
		and as God breaking into the bizarre physicality of the now,
			in bread and wine,
			in word and sacrament,
			in the Spirit blowing through the dust.

I can be both a theologian and a scientist, 
	because each keeps me humble.
Every time I grow too attached to the here and now,
	God reaches out, through observation, reason, and revelation
		to remind me of something greater,
		just beyond my understanding,
		something to reach for
			in curiosity and delight, 
in faith and hope,
and, of course, in love.
I can be at home in my body,
	and yet know this is not my final home
	because I have faith in God who works out a divine purpose
	in frail and fragile and transitory things.
I am here because here is where I am meant to be – 
	now, but not forever.

So, I will ask from you a pilgrim’s blessing,
	and I will give you mine.

Remember that this is not our home.
Our freedom and our hope
	lie in the home God builds within us.

May the Spirit stir you to action and fill you with peace;
May the God of Creation be with you going out and coming in;
And may Jesus who goes before you greet you kindly when you arrive.



Posted by: dacalu | 25 June 2016

Making Choices

I am reminded this month that decisions matter. The choices we make and the way we make them change the world. Some have wondered why I study science and religion, why I study metaphysics. This is why. Decisions matter. How we think about people, how we treat them, and how we hold ourselves accountable – those questions occupy me as a scholar and as a pastor. I want to help people make the right choices.

Metaphysics matters because it deals with the fundamental categories by which we organize our world. What makes a person a person? What do I value? How do I decide? Ethics rests on these fundamental issues. It all seems so obvious until we meet someone – or even a culture – that answers them differently than we do. As an American, it’s easy to say that all people have certain inalienable rights, but we’ve spent 200 years arguing and changing who we think qualifies as a person. It’s easy to say people are responsible for their actions, but we have spent 200 years arguing and changing our rules for who is responsible for what.

We have changed our minds about who we are essentially, what we choose, and what choices are forced upon us. Sexual orientation and gender identity are only two recent examples. What control do we have over who we are attracted to and how we see ourselves? How much freedom are we allowed as individuals to define ourselves? It occurs to me that I have not said anywhere concretely how I think about choice in light of science and faith. So, let me do that here.

As a question of knowledge, I do not trust you to know what you have control over and what you don’t. Nor do I trust myself. Cognitive Neuroscience and Behavioral Economics have demonstrated that we are neither rational actors nor aware of our own irrationality.

Kathryn Schulz, in her 2011 book Being Wrong speaks persuasively about our ability to deceive ourselves. We selectively forget being wrong about things and selectively remember being right, making it hard to understand our processes for moving from one to the other. This, incidentally, is completely in line with Christian concepts of fallibility and pride. Science is putting parameters on something long held by faith and, truthfully, known intuitively.

Daniel Kahnemann (Thinking Fast and Slow, 2013) sums up a longer tradition of research exemplified by Robert Cialdini (Influence, 2006) and Richard Thaler and Cass Sunstein (Nudge, 2009). Some of our behaviors are predictably irrational. Here it is not simply pride or ego that gets in our way – as some have held in the past – but systematic errors in how we look at the world.

Historically, I’m fond of Francis Bacon’s Novum Organon (1620). One of the foundational books for modern science, it introduces “idols” or systematic errors that come from our humanity, personal history, language, and worldview. There is now a cottage industry of such analysis for the general public. Some are better than others, so I prefer work like that of Michael Gazzaniga (Who’s in Charge? 2012) in neuroscience and Kahnemann in psychology. Both writers tie their work closely to scientific findings.

Kahnemann’s analysis in Thinking Fast and Slow offers a real benefit in showing a range of decision making behaviors, from unconscious and automatic to intentional and costly. The distinction allows us to speak about how our conscious selves can help our automatic selves to make better decisions. Conversely, it speaks to how unconscious decisions can work quickly, efficiently, and well in many situations.

We are not devoid of free will, as Sam Harris suggests in Free Will (2012). Nor are we completely free to will and do without limit. I cannot, for example, fly simply by willing it so. I don’t even think I am entirely free in my preferences. In the case of addiction, I think many people will to will other than they do. As Paul said so succinctly in his letter to the Romans (7:15), “I do not understand my own actions. For I do not do what I want, but I do the very thing I hate.” Thus, I say we have constrained will.

Here comes the interesting bit. I know you do not have complete free will, but hope that you have some free will. I aspire to some sliver of control over my action and wish the same for you. Therefore, I will encourage and strengthen the freedom we do have. For if there is no control, then no harm can be done. I cannot offend against the truth if I have no free will at all. I cannot offend, or be held accountable, or change the world for the worse, if I have no control. No harm is done by mistaking a mechanical world for one with freedom.

If, on the other hand, I have some freedom – if even the smallest spark of true choice exists – I have a responsibility to kindle that flame. In Kahnemann’s language, I can devote myself to maximizing my use of rational or slow thinking – not to replace automatic decision making, but to assess it and condition myself to the right kind of mechanical action. There is evidence that hearing, thinking, and talking about free will improves our ability to exercise our freer, more rational decision making (Aarts and van den Bos, Psychological Science 22:532). Perhaps I am a robot, but one that can program itself…

I recognize my constraints, then, as the background for my will. They are obstacles to overcome or, perhaps, tools to use, in choosing rightly. They are the walls of the garden, the meter of the poem, the frame of the painting; they are the edges that make what is inside beautiful, meaningful, and whole.

Christians have been arguing over free will for millennia. We emphasize that many things are beyond our complete control and comprehension – God, creation, even self. We emphasize that God orders the universe and that we are limited by our created, animal, fallen condition. But we also emphasize our role in making choices, in changing, and in growing into the people we are called to be.

Compassion and realism calls us to recognize our constraints, but we must never forget that there is something to constrain. When tragedies occur – and they will occur – and when our neighbors seem to make terrible choices – and they will make terrible choices – we must remember this. It was never about perfect understanding. Rather, it was and is and will always be about understanding more tomorrow than we did today. That will require hope and a constant openness to change the things we can – usually ourselves.

Posted by: dacalu | 9 June 2016

The Call

In 1996, Gerald Soffen received a phone call from NASA Headquarters. Researchers at the Johnson Space Flight Center were reporting evidence of alien life in a Martian meteorite. The discovery was about to go public, the president was going to make a statement, what should he know. Soffen, who had been project scientist for the Viking mission – Martian landers from 20 years before – was the world expert on the search for alien life. What did he think? Was the science solid? There was little time and they needed an expert opinion.

The Allen Hills Meteorite (ALH84001) contains interesting carbon formations that look like microfossils. Seeing the research report, Soffen said yes, this looks like evidence for life, but not proof of life. More work needed to be done. NASA would be accused of hiding the truth if they didn’t say something right away, but the meteorite was promising. On August 7, 1996 President Bill Clinton made a public statement about the meteorite, the possibility that it harbored fossils, and the path of future research.

I was an undergraduate working for Gerald Soffen that summer. To this day, I consider myself both lucky and blessed to have been there. In the coming weeks and years, the scientific community investigated. We found that we were not convinced. Still, the arguments and the evidence spurred the development of astrobiology, a new way of looking at the search for life beyond Earth. Astrobiology integrates of many natural sciences and engineering. The Martian meteorite, along with discoveries of extrasolar planets and extreme organisms, led to a new scientific endeavor. Soffen convinced me to be part of the project. Though it would not be completed in his lifetime, or even mine, it was something important. We should think critically, search thoughtfully, and create an integrated picture of life in the universe.

Twenty years later I dread – and devoutly hope – that I, too, will receive a phone call. “We’ve seen something wriggling on Europa. We need to tell the world. What should we say?” These days I’m one of the experts, not only in astrobiology as a science, but something we call “astrobiology and society.” Life is a tricky concept and it means different things to different people. How can NASA as a public institution respect the beliefs of citizens, while being thoughtful about the science? When the public funds the search for life, what are they asking us to do? And how will they respond to what we find?

In recent years, the NASA Astrobiology Institute has funded several astrobiology and society programs, including a chair at the Library of Congress and a program at the Center of Theological Inquiry in Princeton. These programs do not conflate religion and science. They do give us a chance to think critically about the questions. What makes life interesting? How can we search for life, study life on Earth, and communicate the results in a way that will satisfy the deep curiosity of the general public?

Thinking ahead, we may also have to answer some very difficult questions. If we do encounter life, will we have an ethical obligation to turn off the spacecraft? We don’t want to inadvertently harm something on Europa. That type of question rests solidly on what we, as a society, think about the value of life both on Earth and beyond. I’m proud to be one of the people laying the ground work so that when the time comes, we will be ready. I’m proud of my role in getting the best science to scholars of the humanities and the best of the humanities to scientists. The call may come tomorrow, or in a hundred years, but I think we will be ready.

Posted by: dacalu | 5 June 2016

To Be Human

I was having a discussion yesterday with colleagues at CTI about human distinctiveness – how we differentiate ourselves from other animals. Largely this has to do with privilege – treating ourselves as better or more free – and duty – asking more of ourselves. The issue arises again and again in science and religion discussions. This time it had to do with astrobiology and theology. How does our scientific investigation of the origin, extent, and future of life impact our view of ourselves and our place in the cosmos?

I keep returning to one issue. Most of us think humans are, in some way unique, but what do we mean by “human”? At first the question sounds pedantic and obnoxious. We all know what human is, don’t we? Yes, and no. I want to suggest that we have different distinct ideas about “human” and, though we each know what we mean, we don’t all know what others mean. This will come up in discussions of human dignity, the beginning of human life, and human rights. At stake in all of these will be how you draw the boundaries of humanity. We must take care with words because this discussion centers on what those words mean. In order to ask about human uniqueness, we must understand the way we speak.

Let me start by saying that “human” is both an adjective and a noun. The adjective human refers either to a scientific concept – things related to the species Homo sapiens – or to a related common sense concept – things related to us. I can speak of human tissue, human habitations, human culture. We might quibble, but I think I can use the adjective quite clearly and know that we are communicating.

The noun is more problematic. Historically, it comes from the adjective and it refers to something more specific: a human being. We might say it is a human person, a human individual, or just “a human.” That added word does all the heavy lifting. To take the most political example, no one doubts that a human fetus is human (adj.). No one claims that an alien has found its way into a mother. The real debate has to do with whether it is a human being. Thus the beginning of human life generally must be distinguished from the beginning of >a< human life. The first occurred ages ago. As a society, we debate whether the latter occurs at conception, at birth, or somewhere in between.

Human rights, likewise, do not apply to all things incidentally human. Human hair deserves no unique dignity or privileges. Human beings do.

Too often, people worry that scientific discoveries about humans will weaken our concepts of human dignity. They are mistaken. The science tells us things about human flesh and blood, about human history and human relationships. Human dignity does not suffer when we know about these things. It suffers when we reduce human beings to flesh and blood, history and conditioning. That latter step, that reduction to the physical and phenomenal, has not been produced by science. It was produced by confidence that physical science is sufficient to explain the world.

To my mind, our uniqueness does not come from our flesh. It comes from our freedom, our reason, and our relationships. What we know about the species Homo sapiens and about our flesh is fascinating. It tells us we are related to other animals and to all life on Earth. How could that not be wonderful and empowering. The hard work of rights and dignities does not spring from this flesh – or from this flesh alone. In Christianity (and many other faiths) it comes from something else, something we have always understood poorly and which we hesitantly call the soul.

Any real dialogue about human dignity and human rights, any real dialogue about the uniqueness of humanity or the beginning and end of a life, turns on what it means to be a human being. What additional work is done when we specify not just a human (adjective) thing, but a human being – a human (noun)? That’s where the real conflict lies – not in biology, but in philosophy. Let the reductionists out there defend why they think a human being is only a human biological organism. Let their opponents state what must be added or taken away. But let us all stop simply saying “human” as though we knew what we were talking about. We have a long way to go before we understand our selves.

Posted by: dacalu | 19 April 2016

Astrobio Haiku

A few haiku

on astrobiology

at a party:


– Susan Mix

Floating through the void

of a starry summer night,



– William Mix

Cool celestial peeking

morning sunshine off my face

post messages through time.


– Lucas Mix

Petals fall gently

onto wind harrowed sands;



Pluto and Charon

dance in the fading sunlight;

New Horizons.



unconstrained by numbers

populates the stars.


Drifting through space-time,

life leaves trails of carbon on

unsettled planets.

Posted by: dacalu | 2 April 2016

Silly Humans

The world does not revolve around you. It never did. You’ve heard the story no doubt; we all have. Once upon a time, perhaps 500 years ago, humans were foolish. Our silly ancestors thought they were the center of the universe. Luckily for us, science showed us how unimportant we really are. Copernicus showed us that the Earth goes around the Sun, and not the other way around. Darwin discovered relationships between all living things, reducing us to animals. Freud dove into the depths of the psyche, uncovering just how much our unconscious selves rule our lives. It is one of the myths of our age that we are better off than our silly ancestors, who thought too much of themselves, and too much of humanity.

That much is true. At least I believe it to be true. We have found a humility once lacking in humanity. But who exactly were our silly ancestors? That question matters. I suspect you’ve been told that the silly humans were religious, specifically Christian, while the wise descendants followed the path of reason and science. Not so much. The disciples of reason and science – many of them Christians, of course – were the ones who convinced us we were special in the first place. Indeed, Christians have long held that humans are not so special as they would imagine. So here is the story behind the story.

One thousand years ago, humans counted themselves less wise than we do today. No one thought humanity was the center of the world. And, if you think a bit, you know this… though you may not know that you know. They thought that Hell was the center of the world. The Earth revolved around Satan, as the stars revolve around the Earth. Not the answer you were expecting, was it? Still, if you think about…if you think about what “down” meant 1000 years ago…you’ll realize that I’m right. So let’s get to the bottom of things.

Forget what you were told about Christopher Columbus. Anyone with a decent education knew the Earth was round 2000 years ago. Lucretius thought the Earth was flat just before the time of Christ, but others were catching on. Using trigonometry, Eratosthenes gave us a good estimate of the Earth’s size two centuries before.

Plato and Aristotle both, living five centuries before the Roman Empire, felt certain the Earth was a sphere. Aristotle explained gravity as things falling toward the center. He didn’t get gravitation and mass, but he did know that physics would get really messy if things fell any other way. Not just a spherical planet, but a spherical universe simplified the problem.

Augustine of Hippo (roughly 400 ce), perhaps the most influential theologian in the history of Christianity, points out that Creation could not have taken place in six 24-hour days. That would be silly. The Earth is round and the Sun can’t be shining on all sides at once. The book of Genesis must mean something else.

If the Earth is round, what will we find in the center? Hell. We can blame this on Plato, actually. He writes about the underworld of Hades and below that, deep down in the bowels of the Earth, Tartarus. There the unredeemable suffer fiery punishment for their sins. (Bet you thought that was the Bible. Nope, but that’s a story for another time.) There may be something below Tartarus, but that is as low as Plato goes. Aristotle may have a less heated picture, but even he values heavenly fire above Earthly muck. Down is bad.

Getting back to the late Middle Ages (say 1300), Dante paints a memorable picture of Hell in his book Inferno. The Earth is still round, but now Satan is right in the middle. Of course he’s in the middle, because you can’t fall any farther than that.

So, Satan is face down in the dung heap. Medieval Christians explain this quiet poetically. Humans are messed up. Ever since we broke with God – some nonsense with an apple – we’ve gotten things backward. The true center is God. Everything revolves around God and we orbit at a vast distance – though slightly closer than the Devil.

In our blindness, we invert things, seeing God in the vastness behind the stars. Note, this is not space. Space is the heavens, the sky, the firmament. God is behind those things. Just like saying “beyond the West,” no one took it literally. It meant farther than far. Things got less perfect the closer to humanity they got. And then things got worse.

Whether you have the God-centered cosmos or the inverted cosmos, you realize that humans exist somewhere in between, either in the suburbs of Heaven, or with the flies on the surface of Hell. Being in the middle gave us no pride of place – quite the opposite. We were neither here nor there.

Who told us we were special? The Humanists. Humanism was a movement in the early Renaissance that said people should be our focus. Human perspective, human intellect, and human needs should be the center of our reality.

The earliest Humanists were devout Christians (Petrarch and Erasmus), but by the 18th century people began confusing the study of human nature and human interests with a desire to replace God.

In the earliest days of Modern Science, scholars thought we could know things about the world because we could read the mind of God. Human nature and destiny called us to speak about divine order, invisible to other creatures.

Copernicus thought the Sun was more fitting to God’s dignity than the Earth – hence, it should be the center. [I guess no one told him about the inversion problem.] Darwin had problems with God and humans, but for entirely different reasons; he felt there was too much suffering in the world. And Freud…well we all know he had issues with his mother. He, by the way, was the first to compare himself to Copernicus and Darwin as a scientific revolutionary. Ego, much?

I like humanism. I value science immensely. I just don’t think we can tell this story anymore and pretend that science and humanism saved us from the Christians. Christians know better. Christians know that humans are one among countless species under God’s eye. Read Job if you need convincing.

Christians know that humans are animals. Aristotle called them animals; Augustine called them animals; Aquinas called them animals. Neither our location, nor our bodies, nor our species ever laid claim to be the center of the world. It was our minds. It was the Humanists, and worse, the Enlightenment thinkers who presumed we, and only we, could know the mind of God. We, and only we, could act as the rulers of nature. They put us in the center.

Luckily, this same philosophy pushed us out again. This science that I love dearly, showed us that even our reason is less than we thought it was. Even our reason is no reason to think ourselves masters of the universe.

We must learn to learn the right lesson. We must not continue saying science saved us from faith, especially not if we are advocating for Humanism or atheism. We were never the center of the world until the Humanists told us so. We were never more important than God until the Enlightenment.

Modern science restored a humility thrown away by the Humanists and Enlightenment thinkers as they took the first steps to knowledge. We were, quite literally, sophomores, wise fools who thought we knew more than we did in the first years of our education. If science returns us to humility, it can also return us to an openness to God and to a middling place in the universe – neither above the heavens nor under the dead, but somewhere in-between.

If you don’t see God in the center, I understand. Perhaps you will place something else there, perhaps even humans, but do so with your eyes open. Science will not put us there. Nor will Christianity (or Islam, Buddhism, Hinduism, Judaism…).

If we are better than our ancestors, it is because we grew up. We graduated to an understanding of ourselves as part of something bigger. To put all our hope on science (or mind or reason) would be a step backward. Silly humans.

Posted by: dacalu | 22 March 2016

Batman v Superman

I’m a geek. (“This must be distinctly understood, or nothing wonderful can come of the story I am going to relate.”) That is to say I can geek out about both superheroes and theology. A preacher friend of mine expressed annoyance at being roped into talking about the upcoming Batman v Superman movie. I had the opposite response; what better way of introducing the good news of Jesus Christ? Well, the resurrection and Easter to be sure, but next week there’s no reason every preacher should not be talking about this movie. It reminded me of a song we used to sing at Church Camp. One of the verses goes a little like this:

O, you can’t get to heaven on Superman.

No, you can’t get to heaven on Superman.

O, you can’t get to heaven on Superman,

‘cuz the Lord’s a Batman fan.

All my sins are washed away; I’ve been redeemed.

Why? (Oh Dear Lord, Why?)

First, pop culture is exactly that – popular. It reflects and animates the concerns of people. Otherwise it would not be popular. In this case we have a great reflection of the question of whether we are saved – in a very physical sense – by our gifts or by our hard work. The very premise of the movie, Superman versus Batman, arises because the two heroes exemplify two extremes of what it means to be a hero. Superman is literally a superman. He has inborn gifts that give him the power to deal with the world’s problems in a way no one else can. Batman on the other hand (despite wealth and privilege), has no superpowers. All of his abilities come from hard work, both through training and technology. Batman represents the American dream (or nightmare as the case may be). Batman did it all by himself. And, if that’s not enough, the movie has a plucky hero who’s just as powerful and resourceful, but gets almost no attention because she’s a woman. Add a crazy billionaire peddling fear, promoting war, and trying to take over… there’s no reason you should not be talking about this movie. Merit and cooperation, gender, and politics – any preacher who can’t get to the Gospel from there needs to go back to seminary. I have no doubt my friend will knock it out of the park, once he gets going. So, let me geek out for a bit. I’ve not seen the movie yet; it may be awful (though I have hopes), but it certainly is fodder for some good discussions about ethics and theology.

It’s a Mad, Mad, Mad, Mad World

Batman is a story about about madness, community, and activism. Really. Our story takes place in the city of Gotham. Though New York received the nickname “Gotham City” from Washington Irving in 1807, the name is much older. The town of Gotham in Nottinghamshire is famous for it’s madmen. Legend has it that King John went on procession around England. It was common for the king to move his “court” around the country, so that he could try cases and otherwise do all those governmental things that we now associate with a capital city. The travelling court was important for the running of the country, but it could also be terribly expensive for the locals, who had to provide food and housing for the travelling officials. “Less government” was a very important thing for small towns who wanted the king to pass them by. The burghers of Gotham came up with a plan; they would all pretend to be mad so the King would divert his progress and go someplace else. Gotham became a byword in England for a place where everyone was crazy and neither the government nor community could be trusted.

Batman is a vigilante. He takes justice into his own hands because the community cannot be trusted. Worse yet, there is always a lurking question of whether Batman himself is mad. When he breaks the law in order to serve his personal sense of justice, is he doing more harm than good? Can Gotham be saved, or would it be better to wash our hands of it all together and move someplace else, like Metropolis? Though Batman in the mid 20th century was a much more lighthearted, even camp, figure, the original Batman and the 1980s reboot tackle this moral ambiguity head on.

Look, Up in the Sky

Superman is a story about heroism. From his earliest incarnations, Superman has stood for truth, justice, and the American way. He speaks to the hero that is in all of us, when we let our true nature come out from behind the glasses. The community is fundamentally good, but we need to be protect it from criminals and aliens. Superman is generally viewed as perfect, sound in body and mind with a true heart and an unwavering moral compass. He embodies both privilege and virtue within the context of a healthy community. This rose colored blend of power, nationalism, and ethics has been called into question (most notably in Watchmen and The Incredibles), but Superman retains a squeaky clean, better-than-human image.

Meanwhile, Back at the Ranch

Coming back to the camp song quoted above, I think we can say something important about salvation, by looking at Batman and Superman. Do we think we will be saved (made happy, healthy, and whole; reconciled to God) by struggle (against self and neighbor) or by acceptance (of self and neighbor)? Do we press onward (Philippians 3:14) or let our light shine (Matthew 5:16)? Is it better to see the world as a film noir detective story in which we can trust no one, not even ourselves? Or is it a tale of progress and community where catching the bad guy will restore us to the harmony that is our birthright?

We all need to have the conversation, not because one answer is truly right and the other wrong, but because we all negotiate between the two. We try to understand ourselves as heroes – and as those in need of saving. We are, I think, saved by grace alone, God acting through us and through our neighbors. We are fallen people among our fallen friends. We must struggle and constantly question ourselves and our communities. No magic alien or political savior can save us from ourselves; Each of us has a roll to play in saving the world. And yet each of us has unique and special talents; we should take pride in our excellence – as individuals, as a country, and as a church. We do things no one else can. Above all we strive for justice and peace that extends to and includes everyone. (And yes, there is a magic alien that does the work of saving us; just don’t mistake anyone else for Him.)

I don’t know whether the Lord is more of a Batman fan or a Superman fan. I think they are two sides of the same coin – one urging us to personal greatness, one to a greater wholeness. Sometimes we need to hear from one and sometimes from the other. The scapegoating and radical distrust of this election cycle makes me feel like I live in Gotham City. I think we could use a little more common idealism. The desire for an “outsider” who will save us from ourselves smacks too much of idolatry for me. We could use a little less hero worship and a little more elbow grease.

I believe we are saved by God acting through us. I will be saved through my very geekiness, just as you will be saved through whatever lies closest to your heart. Still, don’t discount popular culture. It tells us what lies close to the hearts of our nation – if only we’ll listen. I don’t care if you watch the movie, but I hope you’ll have the discussion. Are you with Batman or Superman?





Posted by: dacalu | 10 March 2016

The Naming of Organisms

Here is an essay I prepared for the Center of Theological Inquiry on the history of how we name organisms.


What’s in a name? that which we call a rose / by any other name would smell as sweet.[1]


Concepts of names and knowledge within science have deep roots. Just as a genome bears the imprint of many generations of environment, so scientific naming bears the imprint of millennia of arguments about how we know about the universe. These imprints may no longer be useful – or adaptive – but they still impact the way we speak about nature. Such a brief overview can only touch on historical highlights, so I have chosen to focus on the natural-ness of names and how they reflect on the relationship of humans to other things.

Modern nomenclature rests on a foundation of Greek natural philosophy, particularly concepts of “natural kinds” and “differentiae.” Plato introduces the first concept in Phaedrus, oddly enough speaking about kinds of passion. “This, in turn, is to be able to cut up each kind according to its natural joints, and to try not to splinter any part, as a bad butcher might do.” (265e) A hope persists that scientific categories might represent real divisions in nature, rather than arbitrary categories imposed by particular authors. In this way, it is hoped that one truth can be converged upon, from a variety of beliefs. There has been much controversy over whether these “natural kinds” are possible, but I will side with Christopher Shields in saying that some kinds are more natural than others; they are more likely to be useful for a broad range of researchers.[2] Aristotle introduces the second concept when speaking about sciences in Metaphysics (IV). He introduces the idea that we reason with broad categories (genera, sing. genus) in which types (species, sing. species) are distinguished using fixed characters (differentiae). Genera, species, and differentiae have been foundational to scientific naming at least since the eighteenth century.

Aristotle divides sublunary things (imperfect beings, contrasted with the perfect, eternal heavens) into two categories – elements, moved by necessity to their proper region (fire above air above water above earth), and living things, moved by necessity and a soul.[3] The nature (physics) of souls rests in their activity of nutrition and reproduction (vegetable souls), sensation and motion (animal souls), and reason (human souls). Seeking perfection and being unable to live eternally below the heavens, they make copies of themselves, but the types or species of souls remain the same eternally. Thus offspring look like parents. These types and species were common in biology through the Renaissance.

In the eighteenth century, Carl von Linné, picks up on this Aristotelian typology in a particularly Enlightenment way. Aristotle has an etiological nomenclature – based on first principles; Medieval and Renaissance scholars have a relational and anagogical nomenclature – based on the moral import for people; but Linné (or Linnaeus) introduces a systematic taxonomy – intended as a universal and natural ordering. Michel Foucault (The Order of Things 1966) and Margaret Osler (Reconfiguring the World 2010) set forth the metaphysical and epistemological shifts that make this possible. In short, the intrinsic purpose, organization, and order of Aristotle’s souls have been exported to the mind of God, a move that simultaneously promises a comprehensive, well delineated, and replete universe and human comprehension thereof. In his grand work on systematics, Linné states “The Earth’s creation is the glory of God, as seen from the works of Nature by Man alone.”[4] Adam’s role as namer in the garden is extended to scientists in the current day. “The first step in wisdom is to know the things themselves; this notion consists in having a true idea of the objects; objects are distinguished and known by classifying them methodically and giving them appropriate names. Therefore, classification and name-giving will be the foundation of our science.”[5]

Within this frame, Linné divides the world into minerals, plants – which are organized and have life – and animals – which are organized, have life, sensation, and locomotion. He roughly follows Aristotle’s designations according to the vegetable and animal souls. He also speaks of humans as rational animals “endowed with a portion of intellectual divinity.”[6] Our divinity allows us, and us alone (under heaven), to perceive the divine order. (Aristotle makes a similar move with the intellectual soul.) These “kingdoms” of animal, vegetable, and mineral are subdivided into classes, orders, genera, and species, though Linné is quick to point out that “classes and orders are arbitrary; [only] the genera and species are natural.” (ibid.) The last two categories come to be what we call the “Latin binomial” the official scientific name for a species. With Aristotle, Linné was convinced they were eternal, though later in his life careful thinking about hybrids made him question this.

In the 19th century, the eternal taxonomy gave way to a historical and once again etiological theory of biological naming (Foucault, again). Jean-Baptiste Lamarck (Philosophie Zoologique 1809) popularizes theories of evolution and the changeability of species. Charles Darwin (On the Origin of Species by Means of Natural Selection 1859) provides a mechanism, by which such changes could occur, and suggests a single tree of life, through which all organisms might be related. Darwin sets the stage for a new kind of taxonomy, in which organismal names are consistent with their place on such a tree. Willi Hennig (Phylogenetic Systematics 1950) argues that all biological nomenclature should be based on the historical relationships between individuals and groups – not just on similarity, but on evolutionary homology. Important phylogenetic traits are those that two individuals share because they arose once in a common ancestor. The earliest such “phylogenetic trees” tracing common ancestry were based on phenotypes – physical features and behaviors – and parsimony – the rule that simple family trees (fewer changes along branches) are better trees. More recent phylogenies are more likely to use genotypes – gene sequences – and statistical models of mutation.

This shift to “molecular phylogenetics” was facilitated by the discovery of nucleic acid structure and the small subunit of ribosomal RNA.[7] This SSU rRNA is required by all organisms to express genes, resulting in very slow mutation rates. Organisms literally cannot live without it. Nor will they easily suffer changes; the one gene does so much, that small changes can have big effects on fitness. We can identify it in all cellular organisms, making it an ideal molecule for creating universal trees of (Earth) life. Such a tree revealed a vast diversity of life as yet unrealized. The category of vegetable has always covered such a range, but we usually identify it with multicellular photosynthetic organisms, or plants. We now speak of three Domains: the Archaea, the Bacteria, and the Eukaryotes. The kingdoms of Animalia, Plantae (plants in the narrow sense), and Fungi all possess cells with membrane-bound nuclei; thus, they are all within the Domain Eukaryotes. The domain also includes a wide variety of unicellular organisms.

Modern biological nomenclature follows a number of basic rules regulated by international professional societies composed of prominent scientists within their fields. The goal is consistent communication. All require unique Latin (and Greek) binomials composed of a genus and species and the two always come together. Many species may belong to a genus, but no species is genus free. Genus and species must be published in a peer refereed journal with a type specimen – a concrete example of the organism or group – along with specific differentiae allowing other scientists to identify the species. Higher level groupings may also be proposed. Though they are not regulated as tightly as genus and species, the higher level groups also require a type specimen. When conflicts arise, the oldest attribution is considered authoritative. Thus if two organisms have received different names, but are found to be of the same species (or higher level group), the older name is assigned to both. Common Latin binomials include Homo sapiens (humans), Oryza sativa (rice), and Escherichia coli (gut bacteria). The most common groups are, in increasing specificity: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and species. (E.g., Eukaryota, Animalia, Chordata, Mammalia, Primates, Hominidae, Homo sapiens.) Attempts are made for each such group to be monophyletic – comprising all and only descendants of a single common ancestor. Ideally groups also correspond to a clearly identified, adaptive trait. (E.g., humans are in the groups of organisms that possess true nuclei, are multicellular and motile, have notochords, produce milk, Resemble humans, ditto, ditto, and are intelligent. Admittedly the last four groups are very human focused.)

There are formal codes of nomenclature and regulatory committees for naming Animals, naming algae, fungi, and plants, and for naming Bacteria and Archaea. (Note that algae, fungi, and plants do not warrant capital letters; they reflect common names but not accepted monophyletic taxa.) Some unicellular Eukaryotes may fall under the jurisdiction of multiple or no groups. Much debate has arisen in the late 20th and early 21st century on how inclusive or exclusive groups should be. Even at the species level, questions can be difficult. Ernst Mayr made one of the most popular proposals, the “biological species concept.”[8] The BSC holds that a species comprises all and only those individuals of sexual species that can mate with one another. Intuitively helpful and largely successful for animals and plants (restrictive definition), it fails in a few cases (e.g., lions and tiger can mate but their offspring are sterile), and does not apply at all for the vast majority of organisms, which reproduce asexually. Genotypic similarity has been proposed, with a 3% cut-off for species. The solution is logical, but fails to operate as desired. Humans and chimpanzees have less than 3% difference, while E. coli have diversity up to 40%. Some level of arbitrariness remains. The regulatory committees remain emphatic that they regulate the usage of names and how they refer to groups but do not “infringe upon taxonomic judgment” concerning whether the groups are natural or, in any way, objective.

Viral nomenclature follows the pattern of biological nomenclature, though species are even harder to define. Thus strains, identified within a particular lineage of descent and environmental niche, are more commonly named than genus and species. Beyond biology, celestial bodies, geological time periods, and minerals likewise have their own nomenclature, code, and committees. Below the notes, I’ve provided a list of the officials responsible for monitoring each of the codes.

[1] William Shakespeare, Romeo and Juliet II.ii

[2] Shields, C. (2012) The dialectic of life. Synthese, 185, 103–124.

[3] Studtmann, Paul, “Aristotle’s Categories”, The Stanford Encyclopedia of Philosophy (Summer 2014 Edition), Edward N. Zalta (ed.), URL = <;.

[4] Linné, Carl von (1758) Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. 10th ed. Stockholm: Holmiae. p. 3

[5] Linné, Carl von (1964) Systema Naturae. Nieukoop: B. De Graaf. P.19

[6] Linné (1758) p. 3

[7] Watson, J. D. & Crick, F. H. (1953) Molecular structure of nucleic acids. Nature, 171(4356), 737-738. Woese, C. & Fox, G. (1977) Phylogenetic structure of the prokaryotic domain: the primary kingdoms. Proceedings of the National Academy of Sciences, USA, 74, 5088–5090.

[8] Mayr E. (1942) Systematics and the origin of species from the viewpoint of a zoologist. New York: Columbia University Press.


Int’l Code of Zoological Nomenclature

Int’l Commission on Zoological Nomenclature

Int’l Union of Biological Sciences

Plants etc.

Int’l Code of Nomenclature for algae, fungi, and plants (Melbourne Code)

Int’l Association for Plant Taxonomy

Int’l Botanical Congress

Cultivated Plants

Int’l Code of Nomenclature for Cultivated Plants (see here)

Int’l Commission for the Nomenclature of Cultivated Plants

Int’l Union of Biological Sciences / Int’l Society for Horticultural Sciences

Archaea & Bacteria

Int’l Code of Nomenclature of Bacteria (see here)

Int’l Committee on Systematics of Prokaryotes

Int’l Union of Microbiological Societies


Int’l Code of Virus Classification and Nomenclature

Int’l Committee on Taxonomy of Viruses

Int’l Union of Microbiological Societies

Attempts to Unify Biological Nomenclature

Int’l Committee on Bionomenclature

Geological Time

Int’l Commission on Stratigraphy

Int’l Union of Geological Sciences


Commission on New Minerals Nomenclature and Classification

Int’l Mineralogical Association / Int’l Union of Geological Sciences


Posted by: dacalu | 7 March 2016

Reconciling in Body and Spirit

Yesterday, I had the privilege of worshiping with the students at the Episcopal Church at Princeton.  Here is the sermon I shared.


Collect for the Fourth Sunday in Lent

Gracious Father, whose blessed Son Jesus Christ came down from heaven to be the true bread which gives life to the world: Evermore give us this bread, that he may live in us, and we in him; who lives and reigns with you and the Holy Spirit, one God, now and for ever. Amen.



Joshua 5:9-12 (Manna ceases as the Israelites eat produce of the Promised Land)

Psalm 32 (“Happy are they whose transgressions are forgiven”)

II Corinthians 5:16-21 (“in Christ God was reconciling the world to himself”)

Luke 15:1-3, 11b-32 (The Prodigal Son)



Christianity is never abstract.
This is one of the greatest and hardest lessons.
When we feed people, we feed them 
using the the tangible, limited food we have.
	When we tend the sick, we risk infection.
	And when we forgive, we run the very real risk
		of being hurt.
The elder son in today’s lesson is asking good questions,
	questions about economy, justice, and equity.
I do not fault him for asking those questions.
	Nor, if I am to be honest, do I fault him for the answers he finds.
	The father in this story has given the prodigal son more than his share,
		and maintaining the property is important for
		feeding the family and the workers – in this case slaves.
	Shortly before this story, in the Gospel of Luke,
		Jesus asks “Will a person build a tower, without first counting the cost?”
	We should know what we build and what we spend.
I fault the older son because these were the only questions he asked.
	What would be fair?
	What would be reasonable?
	And, of course, Why him instead of me?
He did not ask the other questions.
	What would be loving?
	What would be useful?
	And how does this effect all of our relationships?
Jesus talks about the Prodigal Son, and the Tower, and the Lost Sheep
	to tell us something about God’s extravagant love and mercy,
	which are not opposed to reason and economy,
	but always couched within them.
How do we make the most of what we have – for the good of the world?
I give politicians the benefit of the doubt, both in the church and in the nation,
	because I know they have to do the very hard work
	of working out concrete charity, justice, and economy
	with limited resources.
I know that sometimes I will have to go without
	for others to thrive.
I am most distrustful of politicians when they tell me these decisions are easy:
	that we need only be just and practical
	or that we need only be kind and merciful.
This bothers me most when they invoke Christianity to defend this stance.

Christianity is never abstract.
	It always means making difficult choices, being vulnerable,
		and working with others.
No one said it would be easy.
If you only count the cost in terms of money or food or even equity,
	you will find all of these things are limited.
For the ethicists and economists: these are fixed, finite goods.
	For the biologists and game theorists: we are playing a zero sum game.
	Someone wins and someone loses.
		The elder son falls into this last trap, in particular,
		There is only so much to go around.
		Why doesn’t it come around to me?
	And this is all true, when we speak of money and food and equity.
Jesus tells us to give up our own food and clothing, money and shelter,
	even our own claims to justice under the law,
	for the sake of our neighbors.
		Turn the other cheek, let them have your cloak also,
		Do not take your neighbor to court, give all that you have to the poor.
With Paul, I can preach only Christ, and him crucified.
When we limit ourselves to this discussion,
	When we limit ourselves to thinking about fixed, finite goods,
		then the answer is simple.
	We must give them up, so that others may have them.
That is the bad news, but what about the good news?

The good news is that these are not the only goods;
	these are not the only things we strive for.
There are other goods:
	relational goods like faith, hope, and love;
	open ended goods like curiosity, contemplation, and reason;
	creative goods like art, humor, and wisdom.
We strive for these things,
	and weigh them against the fixed, finite goods.
We choose life and hope,
	giving up the comforts of money, food, even earthly justice, 
	for the sake of a community in the coming kingdom,
	for the sake of eternal life.
“Do not store up for yourselves treasures on earth, 
where moth and rust consume 
and where thieves break in and steal.” (Mt. 6:19)

But that, too would be bad news,
at least bad news for the world,
	if Earthly versus Heavenly goods were all there were to the story.
Give up one for the other.
	Give up the work of God the Creator,
	for the work of God in Jesus.
That doesn’t really work, for it 
	provides a theology where Jesus saves us from creation,
	and from the Creator, 
	a philosophy tried in early Christianity and quite firmly rejected.

The real good news is both better and more challenging.
	John and Paul both go out of their way to say that the Spirit of Jesus
		is the exact same Spirit that was in Creation from the beginning of the world.
Let that Spirit be in you.
	John and Paul go out of their way to say that Jesus took on flesh and blood,
		so that by that flesh and blood we may be redeemed,
		and so that we might claim resurrection in the flesh.

And so we come to my research as a theoretical and theological biologist.
How are we to relate the life of our bodies with the life of our souls?
	How are we to think of physical life and eternal life?
	How are they the same and how are they different?
One major way they are the same, is that they are both you.
	And they are both God.
	You are an organism – but not only an organism – 
and you have in you the Spirit of God –
though, unless you are more saintly than most saints,
that spirit is not – yet – your all in all.
	And the God who walked in the garden at the beginning of time,
		was also incarnate in Christ Jesus,
		in the flesh, of the same stuff as Mary.
In this way, there is only one life, the life of God that brings us into being
	and brings us into new life.
One major way that they are different – the Earthly and the Heavenly life –
is that our physical life 
is subject to decay, sickness, and death,
while our spiritual life will be fulfilled in a resurrection body,
	incorruptible, imperishable, and whole.

And that brings us back to our talk of goods.
Near the heart of our faith – 
our open-ended relationship with God, not our finite store of doctrine – 
near the heart of our faith is this idea that new life comes
on the other side of death.
“Very truly, I tell you, 
unless a grain of wheat falls into the earth and dies, 
it remains just a single grain; 
but if it dies, it bears much fruit. 
Those who love their life lose it, 
and those who hate their life in this world 
will keep it for eternal life.” (John 12:24-25)
We have been promised death and resurrection,
	so we must not be surprised to find that we will die,
	as organisms in death of the body,
	as societies,
	even as a universe.
We will die before we are resurrected.
Beyond that death there will be a greater life,
	but we must also remember that it will be a life like this one.
We do not hope for a different life, but a fuller version of this one.
We hope for a life with food and drink, friends and family,
	unimaginably different, and yet a fulfillment of this our very real,
	very concrete, biological life.
That means we can practice resurrection now,
	we can bring the kingdom near,
	we can live into the body of Christ in these very bodies.

Christianity is never abstract.
We live it out in the practice of charity with limited goods,
	in the pursuit of love with physical bodies,
	and in the way we manage our households,
		our countries,
		and our world.
This Lent, I hope you’ll give some thought to how to use tangible stuff lovingly.
It is not enough to replace the economy of the world with the economy of God.
	It is not even possible.
We must fit the world into the economy of God.
We must think about how the way we treat our bodies
	affects our souls, how our physicality affects our spirituality.
We must share our physical food in a way that makes it heavenly food,
	and Jesus teaches us how to do exactly that, at this table.

I hope you don’t think that’s a miracle,
	at least not in terms of a rare event that breaks the laws of nature.
That’s not it at all, at least not to my mind.
It is an example, a type, and a program
	for God breaking into the world.
It is Christ made flesh so that all flesh might be caught up in the life of God.
	We are sanctified so that we can go out and sanctify the world, in the flesh.
The father of the prodigal son uses earthly food wisely,
	to bring about reconciliation.
“we had to celebrate and rejoice, 
because this brother of yours was dead 
and has come to life; 
he was lost and has been found.”
Each of us can do this, too,
	bring others back from the dead,
	with faith, hope, and love,
	using money and food and medicine,
	but always asking the bigger questions,
	of how all things hold together in Christ.

Posted by: dacalu | 3 March 2016

The Naming of Planets

This week at CTI I was asked to present on how we name the heavens in astronomy.  If you’ve ever wondered how Venus and Io and the Milky Way and 51 Peg b got their names, look no further.

Borrowing shamelessly from T.S. Eliot,

The Naming of stars is a difficult matter,
It isn’t just one of your holiday games;
You may think at first I’m as mad as a hatter
When I tell you, a star must have TWO DIFFERENT NAMES.

First, it is important to distinguish between official names and public names. The International Astronomical Union regulates official designations for astronomical objects or “celestial bodies,” but many of them have common names as well. The IAU attempts some regulation of those as well, for clear communication, but if you really want to call the second star to the right “Bob,” you are free to do so.  Such common names vary from place to place and country to country.

Getting to details:

The names of the planets (in our Solar System) are traditional. Seven planets appear in Plato’s Timaeus corresponding to the major gods of the Greek pantheon (4th c. BCE).[1] With the Copernican move to a heliocentric cosmos, Earth becomes a planet per se, while the Sun and Moon lose their places (16th c. CE). Uranus was discovered in 1781 by William Herschel, who named it Georgium Sidus, in honor of his patron, George III of Great Britain. This was not popular outside Britain, and over the next 70 years was replaced with Uranus, after the Greek god who fathered Saturn as Saturn fathered Jupiter. Neptune was discovered in 1846 by Urbain Le Verrier and a number of names were suggested, but one of La Verrier’s suggestions, Neptune, was accepted within a few years. Pluto was discovered in 1930 by Clyde Tombaugh and completed the set, as Neptune and Pluto were Jupiter’s brothers with whom he overthrew the Titans in mythology. Most of the planets go by the Roman names. The exceptions are Earth (Germanic) and Uranus (Greek).

The Solar System is comprised of eight planets and two belts all orbiting the Sun in a plane (“the plane of the elliptic”). Pluto, at 17 degrees off plane, was already anomalous and when a larger object was found in its region, the IAU downgraded it from “planet” to
dwarf planet.” The term planet now designates an object orbiting a star, large enough to form a sphere under gravity, that has cleared the neighborhood of other objects. Dwarf planets are spherical, but had not cleared the area.

The term minor planet refers to other objects orbiting a star. Most minor planets are asteroids or comets. Asteroids are rocky (more carbon and silicon, less water, hydrogen, and helium) minor planets, mostly orbiting in the asteroid belt between Mars and Jupiter. They are thought to be the remains of a planet or a planet that never formed and include the dwarf planet Ceres. Asteroids sharing Jupiter’s orbit are called Trojans and are named for Trojan heroes. Asteroids orbiting from Jupiter to Neptune are named for Centaurs. Other asteroids are open to naming, with minor rules and an exclusion of military or political figures within the past 100 years. Comets are volatile (more water etc.) minor planets whose orbits take them beyond Neptune. They receive official codes (e.g., Comet Hale-Bopp was originally designated C/1995 O1). Some exceptions are made, as with Hale-Bopp and Halley. Most comets orbit in a belt (the Kuiper Belt) near the plane of the ecliptic beyond Neptune, and as such are designated Trans-Neptunian Objects (TNOs). They include the dwarf planets Pluto, Eris, and Makemake. Those that receive names, are named for underworld deities or creation deities, depending on their orbital dynamics. The object that resulted in downgrading Pluto was named for Eris, the goddess of strife.

Moons and Planetary features are named by convention (see USGS and NASA pages) :

Mercury – named for the messenger god because of it’s swift orbit

No moons. Features named for artists and explorers

Venus – brightest star, named for the goddess of beauty

No moons. Features named for women: historical, fictional, or mythical

Moon – satellite of Earth.

Many classical feature names

Features named for scientists and mathematicians

Mars – named for the god of war, possibly due to red color

Phobos and Deimos named for Mars’ attendants, fear and dread (horror and terror); Phobos’ features named for characters in Gulliver’s Travels

Many classical feature names

Features named for towns

Jupiter – named for the Roman king of the gods

3 rings and 67 moons named for Jupiter’s “lovers and favorites” (1975) and daughters (2004) (Galileo wanted to name them for the Medici, but they are now known as the Galilean moons, after Galileo. Theses first four were named by Simon Marius in 1610, but called Jupiter I, II… until the 20th c. when Marius’ names were revived.)

Saturn – named for Jupiter’s father, slowest orbit among the classical 7

7 rings and 62 moons named for Titans (proposed by Herschel in the 18th c.) and other giants

Uranus – named for Saturn’s father

13 rings and 27 moons named for characters from Shakespeare’s plays and Pope’s “Rape of the Lock”

Neptune – named for the god of the sea

6 rings and 14 moons named for water gods and spirits


Stars often have names based on classical usage, including Flamsteed’s star atlas (early 18th c.) or Gliese’s index (1957). Extrasolar planets can be named for their star or their discovering instrument (e.g., Kepler) along with a lowercase letter, if there are multiple planets in the system. [Upper case letters are used for binary stars…] A few extrasolar planets have also been given semi-official popular names by public contest and committee approval. Galaxies, nebulae and other large features have designations. Historically these started with Messier’s Catalogue (1771). The Milky Way is a feature of the sky named by the Greeks for the appearance of milk spilled across the sky. Thomas Wright proposed this as a structure of stars in 1750 and Immanuel Kant first explained it as a galaxy in the modern sense in 1755.


[1] 38b-40b. Plato says he is describing the nature (physis) of the visible and generated gods (40c). These include Gaia (Earth), the greatest. Above Gaia are Selene (the Moon), Helios (the Sun), Hesperus (Venus), and Hermes (Mercury) in ascending order. The final three would have been Ares (Mars), Zeus (Jupiter), and Cronus (Saturn). There are probably older references, but this is the earliest I have on hand.

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