“Scientism” is often taken as the claim that science can answer all questions. Of course there are plenty of things that scientists don’t currently know, so the suggestion is, instead, that science could potentially answer all questions, or at least all meaningful questions.
For example the philosopher Julian Baggini says that
“What is disparagingly called scientism insists that, if a question isn’t amenable to scientific solution, it is not a serious question at all.”
Another noted philosopher, Massimo Pigliucci, writes in his book Nonsense on Stilts :
“The term “scientism” encapsulates the intellectual arrogance of some scientists who think that, given enough time and especially financial resources, science will be able to answer whatever meaningful question we may wish to pose …”
I disagree with these definitions (both of course by people critical of scientism), and suggest that scientism is instead the claim that science can answer all questions to which we can know the answer. The point is that there are many questions that are “meaningful”, yet we can never, even in principle, answer them. First let’s distinguish between meaningful and meaningless questions.
Meaningful questions that science can answer
Critics of scientism often assert that historical questions are outside the realm of science, as are questions within axiom-based systems such as mathematics and logic.
Defining science broadly as enquiry based on empirical evidence (which I defend more extensively here), history is just as much an evidence-based subject as any science, and there is no basis for asserting a fundamental demarcation between them. Indeed paleontology, geology and cosmology are all sciences that are largely about the past, and which deduce the past from the evidence that the past has left in the present. And that, surely, is what historians do. Any boundaries between human paleontology, archaeology, and history are arbitrary, and there is no basis for asserting that somewhere along the historical record such study changes from a science to a non-science.
As for mathematics, it is often asserted that mathematical truths derive from reasoning from axioms, and thus are fundamentally different from truths derived from empirical evidence. However, where do these axioms come from? They are not arbitrary, and they are not arrived at ex nihilo, instead the axioms of mathematics are products of our observation of the universe; they are distilled empirical enquiry. Why else have mathematicians chosen their particular axioms, other than the fact that they work? By “work” I mean produce results, such as 2 + 2 = 4, that accord with observations of our empirical world.
Philosophers have puzzled over (in Eugene Wigner’s phrase) the “unreasonable effectiveness of mathematics”, yet much of the puzzle disappears when one realises that mathematics is a distillate of our empirical experience of the universe; why is it surprising if it then works well when applied to the empirical universe?
In an essay Geometry and Experience Einstein asks:
“At this point an enigma presents itself which in all ages has agitated inquiring minds. How can it be that mathematics, being after all a product of human thought which is independent of experience, is so admirably appropriate to the objects of reality? Is human reason, then, without experience, merely by taking thought, able to fathom the properties of real things?”
He then answers with a “no”, and argues that the premise of the above question is false, that mathematics is derived from human experience, and that:
“Geometry thus completed is evidently a natural science; we may in fact regard it as the most ancient branch of physics. Its affirmations rest essentially on induction from experience, but not on logical inferences only”.
We should also remember that “human thought” is a process occurring in our brains, brains that have been molded and programmed by eons of empirical brute facts — namely the operation of evolution by natural selection. Our brains think as they do precisely because, over evolutionary time, that way of thinking has proven to be in accord with the empirical universe and thus useful to our survival and procreation.
Mathematicians arrive at axioms by distilling empirical observation and by using brains that are themselves a record of past empiricism; they then reason from the axioms (using logic that is also a distillation of our experience of the universe, deduced by those same brains) and arrive at new mathematical truths. It is misconceived to then claim that the resulting truths are in no way empirical.
Questions that are not meaningful
A common criticism of scientism is that science can not arrive at moral truths, it can not tell you what you ought to do, or tell you what is morally right or morally wrong. You cannot get an “ought” from an “is”, and science tells you only the “is”. This claim is correct. Does that refute scientism? No it doesn’t, because there are no such things as abstract moral truths.
Science can’t tell you what is morally wrong or morally right, because the very concept of an abstract moral truth has no meaning. Moral sentiments and moral claims are opinions, they are feelings, and they cannot be divorced from the sentient being having the opinion or feeling. Moral rightness and moral wrongness are not fundamental properties of the universe that can be established in the abstract, they are feelings that we have, that evolution has programmed into us as a means of enabling our highly social and cooperative way of life.
If you disagree with this stance, if you insist that morality must have more foundation that this, if you feel this in your gut, then that shows how good a job evolution has done of programming you to be a moral being. And evolution has programmed you, not because morals are a fundamental truth of the universe, but for the entirely pragmatic reason that morals help us get along with our fellows. And they work better if you feel that they are absolute, and have a higher status than mere opinion, and so evolution has programmed us to think that.
Once you properly understand what morals are you realise that the realm of morals is entirely within the domain of science, because the only proper moral questions are of the form “Does Jane think that that act is moral?” or “Do most people regard this act as moral?” or “Why do people think that such and such is immoral?”, and those are questions about highly evolved mammals that science has the correct tools to answer ( I defend this argument more extensively here).
Meaningful questions that science cannot answer
Despite being a defender of scientism I accept that there are many questions, quite meaningful ones, that science cannot answer, even in principle, even with the most advanced technology conceivable. This is compatible with scientism provided that no other form of human enquiry can answer them either. Here are some examples:
Loss of information over time:
What are the names of everyone who ever fought in one of Alexander the Great’s armies? Who fired the arrow that hit King Harold in the eye at Hastings (if that did indeed happen)? What did Julius Caesar eat on the day three days before his fifth birthday? Did he stroke a dog on that day? All of these seem to me to be meaningful questions, in the sense that they would have proper answers, but almost certainly we can never know these answers because the information needed to know them doesn’t exist.
Information is a pattern, and patterns tend to degenerate over time and be destroyed (in accordance with the second law of thermodynamics). Thus, even if we knew everything about our current universe, we likely could not answer the above questions and vast numbers like them.
Finite light-travel time:
Relativity tells us that information cannot be conveyed at faster than the speed of light. Therefore there is an observable horizon, at a distance given by light speed multiplied by time t, and we can obtain no information from beyond that horizon about anything more recent than t ago. So many questions of the form “What is happening now in distant place Zog?” are unanswerable, even in principle. They are still meaningful, however, and in principle we could, later on, get information about what had happened at that time and place. [There is a possible get-out here, owing to quantum “spooky action at a distance”, and it is unclear whether this voids the above argument; we need a proper understanding of quantum entanglement to know for sure.]
The Heisenberg uncertainty principle of quantum mechanics tells us that there are limits to the amount information that we can obtain, in particular it says that pinning down one quantity precisely can inevitably means that another quantity is less accurately knowable. [A caveat: I suspect that this one should properly be in the category of not-meaningful questions, in that knowledge that violates the uncertainty principle would be incompatible with the basic nature of a quantum system.]
The observer effect:
Suppose we want to know the state of an electron. How can we find that out? We can’t just “know” it, we have to prod it somehow, for example by bouncing a photon off it. Yet that photon (and any other prod) has energy, and so will disturb the state of the electron. We can therefore only learn about the prodded state, not the unobserved, un-prodded state of the electron. Most of the time we can use a sufficiently minimal prod that this doesn’t matter, but we have no zero-effect prods, and thus there are fundamental limits on what we can know.
[Philosophers might want to declare that questions about the unobserved, un-prodded state of an electron are meaningless, precisely because we can never know them. Physicists usually prefer to regard the questions as meaningful but unanswerable. However, this topic can get into deep questions about the “collapse of the wave-function” in quantum mechanics that are not fully understood.]
Lack of information-storage capacity:
What are the current locations of every particle in the observable universe? This is unanswerable, since the answer would have to be assimilated, stored and presented somehow, and that would take storage capacity, which would have to be constructed out of particles. It would take many particles of storage to store the answer for each particle, and therefore we could never obtain an answer for “every” particle.
It is meaningful to ask what the weather will be like this time next year or in a thousand years time. However, our ability to answer is severely limited. Deterministic chaos means that in order to extrapolate information further and further into the future you need more and more information to higher and higher accuracies. Yet we are limited as above, by quantum indeterminacy, by the observer effect, and by limitations on information-storage. Also, the finite light-travel time comes into account, in that the future can be affected by effects propagating from regions currently beyond our observable horizon, from which we can’t get current information. The sum of these effects severely limits our ability to answer questions, even in principle, about the future.
So, to summarise, and contrary to Massimo Pigliucci, “scientism” is not the claim that science can answer “whatever meaningful question we may wish to pose”, it is the claim that no non-scientific method of enquiry can obtain an answer that science cannot. Scientism is the view that knowledge of our world is a unified whole, with no fundamental divisions into incompatible domains, and that empirical enquiry is our best and only method of obtaining such knowledge.