# Is Science a Threat to Religion?

*Johannes Siedersleben, Oxford, August 2023*


Given the fate of Galileo (house arrest), William of Ockham (exile) or Giordano Bruno (death at the
stake), it is tempting to say that it is the religion that threatens science. The relationship between
science and religion has always been an uneasy one, fraught with mistrust, misunderstanding and
mutual recrimination. The purpose of this paper is to explain what science really is, and why science
is a challenge but not a threat to religion. To do this, I will clarify terms in section (1) and take a
historical look at that uneasy relationship in section (2). I will then explain the nature of science in
three sections: classical physics (3), modern physics (4), and evolution (5), leading us to the desired
conclusion. In section (6) I will talk about the veil that separates the perceivable world from
everything else, if there is such a thing. I will conclude with two appendices: 
the first (A) on the Darwinian evolution of systems such as physical or moral ones,
and the second (B) on the truth and reality of physics.

## 1 Science
It is important to be clear about what we mean by science. I propose to distinguish hard science,
soft science and non-science.

Hard science (or natural science) includes mathematics, physics, chemistry, biology, medicine and so
on. It is governed by two irrevocable rules, tacitly accepted by the global community of researchers:
(1) The only accepted tools are repeatable experiments, and logical reasoning, which includes
mathematics. (2) Everything can be called into question, except these two rules. I deliberately do not
include the claim of falsifiability, which is an interesting property, but subject to many objections
(falsifiable by whom and when – now or in a million years?). In hard science, doubt is essential,
certainty often delusive. Anyone, and especially any competitor, has the right to challenge the experiments
carried out by another, to question his reasoning and even his method, so much so that hard science
has always presented itself as an eternal discourse that will never reach a conclusion; the list of open
questions is growing much faster than the list of resolved ones.

In soft sciences, rule (1) is relaxed, while rule (2) is maintained, which forbids any kind of
prejudice, any limitation of thought. Soft sciences include law, history, literature, political
science, religious studies, philosophy and so on. They are, in a much stronger sense than the hard
sciences, an eternal discourse because they lack a criterion of truth. 
Who is right? Plato or Aristotle, Hume or Kant, Hajek or Keynes? 
They all have good points, but none is decisive.

The term *soft* is by no means pejorative. But soft sciences will never be anything other than a succession of
competing theories that emerge, are tested, sometimes applied and often disappear. There will never
be an ultimate legislation, an ultimate political system, let alone an ultimate ethics.

Non-science relaxes both rules and is open to every kind of prejudice and limitation of thought.
Theology is not science because it presupposes a particular belief: you have to be (or fake to be) a
Catholic to study the Catholic religion, a Protestant to study the Protestant religion, or a communist
to study dialectical materialism in Moscow under Stalin. Homeopathy is not science, nor is any kind of
superstition. The term *non-science* sounds pejorative, but it's not meant to be. Theological studies or
studies of Marx can be enlightening and rewarding, and homeopathy may well work in some cases.
But these disciplines don't meet the criteria of science. Philosophy of religion, by definition, straddles
the boundary between soft science and non-science.

Does soft science threaten religion? While it is hard to see how, for example, the science of law
or history could be a threat to religious belief, philosophy plays a different role. At its heart are three
questions: what is true or false, what is good or bad, and how do we know? So religion is an obvious
object of philosophical inquiry, and religion has to accept the challenge as part of the game, but by no
means as an existential threat. It goes without saying that philosophers are allowed to use the hard
sciences as a toolbox without exposing themselves to the charge of scientism.
As for the boundaries between hard science, soft science
and non-science, there are of course grey areas such as psychology, but that is irrelevant to our
discussion. It is worth noting, however, that many eminent scientists wear two hats. Albert Einstein,
the physicist, wrote a booklet, *On Cosmic Religion*, in which he presents a pantheistic view of the
world. Bertrand Russell is famous as both a mathematician and a philosopher. The most notorious of
all is Richard Dawkins, renown as a biologist and as a critic of religion. His book *The Selfish Gene*
(hard science) tells the story of evolution, and his book *The God Delusion* (soft science and
heavily criticized for scientism) is a philosophical examination of the fallacies of religion.

### 2 History
Let us begin with the Greeks. 
Before about 600 BCE, everything was down to the gods: sunshine, rain, hail and thunderstorms.
Anaximander of Milet, a pupil of Thales, was the first to question this attitude. He correctly observed
that rain is the moisture that had risen from the earth. This was the beginning of science, 
but there was still a long way to go. Plato (d. 348 BCE) despised scientific experiments, 
which he considered
unworthy of a scholar. Aristotle (d. 322 BCE), on the other hand, carried out many experiments, but his
results were largely wrong, both in physics and in logic. If the Greeks, with a few exceptions such as
Archimedes and Eratosthenes, were not good at scientific experimentation, they were excellent at
criticizing each other. Rule (1) was still being debated, but rule (2) was definitely in force. The Greeks
were free thinkers in every sense of the word. They followed their own ideas fearlessly, without
concern for where they might lead. Greek scientists and Greek gods lived peacefully side by side,
neither threatening the other.

Theodosius I's edict of intolerance in 393 CE put an end to freedom of thought. Before the council of
Nicea (325 CE) it was dangerous to be a Christian, after 393 CE it was dangerous not to be one (think
of Hypatia of Alexandria). The scholars of the Middle Ages considered that all the conceivable
knowledge of mankind was already recorded either in the Bible, or in the writings of the Church:
Fathers such as Jerome, Ambrose and Augustine, or, at most, in selected Greek works: Plato, yes,
Epicurus, no. What wasn't there was false, useless or both. The library that plays such a central role in
Umberto Eco’s *The Name of the Rose* was a closely guarded place for locking up knowledge, not for
disseminating it. In the Middle Ages, the Church was more than a threat to science: scientists and
philosophers had to toe the line to avoid being burned at the stake.

It was Martin Luther (d. 1546) who dealt the final blow to the Middle Ages: a little monk from
nowhere opposed the Emperor and called the Pope Antichrist. Luther succeeded in profoundly
undermining the authority of the Church, paving the way for the scientific Renaissance and, later, the
Enlightenment. The hard sciences got off to a shaky start with men like Copernicus, Kepler, Galileo,
and Francis Bacon. Copernicus did not publish his work until shortly before his death, with an
interesting preface: It said that the reader might indeed be led to believe that the Earth revolves
around the Sun. But this would only be a working hypothesis, which, for complicated reasons, makes
calculations easier. In reality, of course, the Sun would revolve around the Earth. So the Church
continued to threaten science well into the 19th century. It was not until 1822 that it conceded that
the Earth orbits the Sun, and the theory of evolution was half-heartedly accepted in 1950.

Since Copernicus, the development of science has been like a series of rockets, each building on the
previous one and picking up speed: Descartes and Pascal, Newton and Leibniz, Darwin and Wallace,
Einstein and Poincaré, Heisenberg and Schrödinger, Turing and Alonso Church are just a few prominent
examples, and after 1700 or so nobody had to fear a terrible end at the stake. 
Religion was no longer a threat to
science, and some theists claim that now the roles were reversed. For them, the discoveries of the
Enlightenment, from Newton to Darwin to Einstein, were as many blows to religion. And they see
every unsolved scientific problem, every phenomenon that science cannot explain, as a bulwark to be
defended against the attacks of science. They are, of course, dead wrong. To see why, let us look at
three prominent examples: classical physics, modern physics, and evolution.

### 3 Classical Physics
I will use classical mechanics to make my point, which is to explain the nature of classical physics and
what it means for religion. Classical mechanics includes the law of gravity, Newton's three laws and
the equations of motion. It has been accepted by virtually everyone except a few stubborn people
who insist on taking the Bible literally. This is remarkable for two reasons: (1) Classical mechanics is
counterintuitive because it says that a particle, with no forces acting on it, will move in a straight line
forever. Have you ever seen anything like this? And imagine you were 400 years back in time and
someone told you that as you sit here the Earth is moving through space at 67,000 mph. What would
you have said? (2) Classical mechanics contradicts the Bible: It says that the Earth orbits the Sun and
that a point of absolute rest is impossible.

Technically, classical mechanics is based on the concept of volume-less particles and two principles:
the principle of symmetry (you can't tell which train is moving) and the principle of least action, which
says that every object behaves in a way that causes the least amount of mess. Everyone is free to
develop their own mechanics based on the principles of their choice, but these two have proved
extremely useful. From the concept and the principles mentioned you can derive the equations of classical
mechanics from your armchair using mathematics. And back in your lab, you'll find your results confirmed.

Conceptually, classical mechanics is a model in our
brain (or on paper, in computers) that happens to fit (or to model) reality in such a way that we can
make predictions: we can calculate the fall of a raindrop, the trajectory of a ball, the flight of a rocket,
and virtually any motion if we know the masses and forces. It cannot be emphasized enough that
such a model is nothing more than a description of reality with some limited precision. A falling stone
is completely ignorant of Newton, stones have always fallen in the same way. To say that a stone falls
the way it does *because of Newton’s laws* would be completely wrong. There are alternative models,
such as those of Aristotle, of Einstein and of quantum mechanics. While Aristotle’s model is useless
and forgotten, the other two are more accurate than Newton’s, have a wider scope but are more
complicated. Physics provides models, such as that of classical mechanics, which are 
more or less useful, more or less accurate. Does it also provide truth? We'll come back to this 
question in section (4).

I said that classical mechanics can be derived from an armchair using mathematics. Imagine this: You
start with two innocent principles, you calculate a few pages, and you end up with a model that
describes the world. *Why does mathematics work so well?* This is really mind-blowing and makes
even the most hardened atheist pause for thought. Einstein's booklet *On Cosmic Religion* is all about
this miracle. Is it explicable? The debate is ongoing.

For the atheist, this is where the story ends. The theist might ask: who made the whole thing? Did He
just create reality, or did He provide the models at the time of creation for later use? How does He
ensure that all objects, even in the darkest corners of the universe, behave in the same way forever?
Does He really? The theist is free to choose his preferred answer without interfering with hard science.
Hard science completely ignores his choice, it ignores religion altogether. There is no conflict at all,
unless the theist takes the Bible literally. But then no dialogue is possible.

### 4 Modern Physics
I will use relativity and quantum mechanics to make my point, which is to explain the nature
of modern physics and what it means for religion. Relativity and quantum mechanics are
models in exactly the same way as classical mechanics. Classical mechanics fails when there are two
or more observers travelling at high relative speed, and it also fails when distances get close to the
wavelength of light. Relativity comes in for high speeds (but is valid for all speeds), and quantum
mechanics comes in for small distances (but is valid for all distances). Both theories generalize
classical mechanics, which is a special case of both. We could discard classical mechanics altogether
and replace it with one of the two modern systems, but we prefer simplicity to a precision we don't
need. Relativity postulates a third principle in addition to the two we have seen, namely that
the speed of light is the same for all observers, no matter how fast they are travelling. Like all
principles, the constancy of the speed of light is only an observation that cannot be proved. Quantum
mechanics does not require any additional principles, but it replaces the volume-less particles of
classical mechanics with wave functions, which can be used to calculate the probability of a particle
having a particular property, such as position or momentum. Given the concepts and principles involved, 
you can use mathematics to derive both theories from your armchair. 
However, the mathematics of quantum mechanics and general relativity is more complicated. 
And again, back in your lab, you'll find your results confirmed.
So the miracle goes on and on and on. Imagine all these famous
and utterly unfathomable results, such as *E = mc<sup>2</sup>*, Schrödinger’s equation, or the Heisenberg
Uncertainty Principle, popping up after a few lines of calculation using mathematics that existed long
before. A puzzling question remains:
How on earth could someone (in this case Schrödinger) come up with the outlandish idea of
replacing particles with wave functions? Is this another miracle? Evolution might be an explanation,
I'll return to this point in section (5).

Classical mechanics is counterintuitive, but we are somehow used to it. We simply believe that we are
moving through space at 67,000 mph, we see cars driving and planes flying – physics seems to
work. But relativity and quantum mechanics are not only counterintuitive, they defy our reason.
Relativity involves time dilation, length contraction and a host of paradoxes that no one can imagine or 
intuitively understand. And yet, they follow easily from the equations.
Quantum mechanics is even worse: small particles no longer exist; the equations
give probabilities rather than certainties. And then there is quantum entanglement, the basis of
quantum computers, which leaves you stunned. What does this mean for questions of
existence, of causality? Are these problems just problems within physical models, or are they
somehow real? Do electrons really exist? No one has ever seen one directly, but you 
have the equations, and you have dots on a screen that represent electrons, if you believe the machinery.
Has our common sense become useless or misleading? The bad news is that both
philosophy and religion have the enormous task of digesting these results and adapting their existing
teachings accordingly. But this is a challenge, not a threat. The good news, at least for the theist, is
that modern physics is so weird that it doesn't raise any new contradictions with the Bible. So this is
where the story ends for both theist and atheist.


### 5 Evolution
In his book, *On the Origin of Species*, Darwin conveys two messages: (1) the evolution of animals from
single-celled organisms to Homo sapiens and (2) the mechanisms of mutation and selection. When he
says that animals evolved over millions of years, he contradicts the Bible in at least two ways: first, he
claims, animals were not created in one day, and second, they were not perfect. If they had been
perfect at the time of creation, as many theists purport, there would have been no need for
evolution. But Darwin says nothing about the Creator. He is NOT claiming, as some pretend, that
everything happened by itself or by chance. Rather, he says what happened, what the mechanisms
are, and that's it. Darwin's tree of species is simply a map showing how species appeared, evolved
and often disappeared. White spots on the map may or may not be filled in in the future, depending
on the evidence available. They are not an argument against evolution. This map has been rigorously
tested using DNA-based methods and found to be completely accurate.

The mechanism of mutation and selection can be easily verified in a test tube using rapidly reproducing
bacteria. As for selection, a word is in order: selection in the sense of
*survival of the fittest* is a tautology, there is nothing to
prove and nothing to deny: The living species are those that haven't disappeared, just as the living
people are those that haven't died, the standing buildings are those that haven't collapsed,
the existing religions are those that haven't disappeared, the companies that are in business are
those that haven't gone bankrupt, and so on. This obvious fact is sometimes forgotten: standing in
front of an ancient building, some visitors would say to themselves: oh yes, the builders of yesteryear
knew how to make their work last. But these visitors are admiring a building that happens to be still
standing, regardless of the many that have disappeared. The next paragraph should sound familiar.

For the atheist, this is where the story ends. The theist might say, without interfering with Darwin: 
There must be a Creator who set the whole process in motion. Does He have a laboratory 
to design complicated organs like the eye or the brain? Does He use a joystick to control the rise 
and fall of species? The theist is free to choose his preferred answer without interfering with hard science. 
Hard science completely ignores his choice, it ignores religion altogether. There is no conflict at all, 
unless the theist takes the Bible literally. But then no dialogue is possible.

Evolution deniers are left with no target: denying Darwin's message (1), evolution, or message (2), selection,
is as absurd as denying Newton's law, and that's all there is to object to. The famous dust bomb argument
misses the point. It is, if anything, an argument against evolution 
being entirely by chance, a claim that no one makes. The bomb, of course, will never make a plane, no matter
how many trillion times you fire it.


### 6 The Veil
We humans are an insignificant species, tiny creatures, living for a few world seconds on a planet that
is not even a grain of dust in the universe, equipped with the senses and the brain that evolution has
happened to give us. We don't smell carbon monoxide because it hardly exists in nature, we have no
sense of radioactivity because the little to be found doesn't threaten us. Yes, we have managed to
build powerful tools for analysing and understanding the world, but are we allowed to think that
what we perceive is all there is? No, I don't think we are. Science is limited to logic and perception;
logic is limited to what our brains can think; perception, by definition, is limited to what we can
perceive. Imagine this: In addition to the four fundamental forces of physics, there could be a fifth
force that can only be detected by senses that are not available to us, and that, at long random intervals, 
produces side effects we can perceive. Such a force cannot be ruled out, and the observed side effects would be
considered miracles. So there is a veil that separates the perceivable world from everything else.
This veil is indisputable, unless you claim that what we perceive is all there is.

What do I learn if I don't? First of all, I become humble. Modesty is an essential virtue of science: the
awareness that there is a lot we know and can be proud of, but that there is a lot more out there that
we don't yet know, and even more that we will never know. Secondly, it makes me resistant to any
attack by supposed or real miracles. Supposed miracles are easily debunked. But consider a phenomenon 
that has been witnessed beyond any
reasonable doubt and cannot be explained by the available science. No problem! It is just another
challenge for science, which may or may not be met. And if not, don't worry! No one is claiming that
science can explain everything! A famous example of a then inexplicable phenomenon is the slit
experiment, in which electrons are sent through two slits at a rate of one per hour, per day or per
year, and waves are detected on the other side. This experiment is one of the roots of quantum
mechanics, which explains the phenomenon perfectly. To repeat my story from section (3) on models,
I'd like to stress that quantum mechanics is just a model (a set of equations) that allows us to predict
what is happening: to calculate how the observed waves depend on the frequency and energy of the
electrons sent. There is no point in arguing about the truth of the model. It may one day be replaced
by a better one, perhaps simpler, perhaps more accurate. But for now, physicists are quite happy with
it.

For the atheist, this is where the story ends. The theist might say: Oh yes, that's fantastic! It's behind
the veil where God lives, where the ghosts are, where my ancestors float around and send me signals
and so on. Fair enough, why not? But who cares?



### Appendix A: Evolution Revisited
The evolution argument can lead us a long way: I said earlier that both the hard and soft sciences are 
an eternal discourse, a sequence of competing theories that come and go without ever reaching a conclusion.
Let's assume that selection also applies to physical theories: the ones we use (Newton, Einstein,
quantum mechanics) are the ones that haven't disappeared like those of Aristotle and countless others:
published, criticised, refuted, forgotten. Then Schrödinger's brilliant idea 
(replacing particles with wave functions) is like a building still 
standing among many others that have collapsed. But all physical theories may be replaced by better ones. 
Now, take the question of morality:
Moral systems have varied greatly throughout human history and across the countries of the world: 
we have seen human sacrifice, torture, capital punishment, slavery, vendetta, all of which seem to have been 
outlawed by now, at least in most Western countries. Here is the argument: 
Societies benefit from a good moral system, they have a better chance of survival. Vendetta, for example,
is a bad system that undermines the future of the country, so it is almost gone.
If it is true that moral systems are subject to Darwinian selection, then they are unlikely to 
converge on an ultimate solution. All imaginable moral systems compete on the same battlefield, and some turn out
to be more successful than others. The liberal, democratic systems many of us prefer is by no means
granted to be the ultimate solution, it is just one of many competing systems. We are all a part of an 
eternal discourse, taking sides, defending our favourites and fighting all the others.
Notice that this is exactly the opposite of the anything-goes attitude of moral relativity.


### Appendix B: Truth and Reality
Here is another question: Given their precarious existence, can physical theories contain any kind of 
truth? If anything, classical physics is true in an ideal space with no friction and dimensions that 
go straight to infinity. But there is no such ideal space.
As far as I am concerned, I am quite happy with the subjective value of models in terms of usefulness and 
insight, and I see little interest in the search for a higher truth. Moreover, truth is generally 
thought to be immutable, absolute, in stark contrast to the tentative nature of scientific theories. 
We can replace theories, but not truth. 

A related question is that of reality. How real are the physical laws?
Again, I am quite happy with the idea that theories exist in our brains and that they only describe 
nature without being part of it. A falling stone is unaware of Newton's laws, a whirling leaf is 
unaware of the equation of motion that governs its trajectory. I cannot see, for example, 
what it means to say that *an electron is real*. We have the equations, we can predict the outcome 
of experiments, and that's quite an achievement.  We have to give up good old ideas such as 
simultaneity, time and much more. We can give up outdated theories, but not reality.


References
[1] Law, S. ‘Scientism’, in (eds.) Pigliucci, M. and Boudry, M. Science Unlimited (Chicago
University Press 2018)