Category Archives: Science

The Second Law of Thermodynamics made easy

The Second Law of Thermodynamics is one of the few scientific laws that has attained a status in wider culture, even featuring in rock tracks by Muse. Famously, C.P. Snow cited an understanding of the 2nd Law as something that every educated person should have.

The 2nd Law is often stated in technical language that makes its meaning hard to understand, but the basic principles are actually readily grasped. I was recently challenged to explain the 2nd Law at the level of a bright 13-year-old, and so here is my attempt. Continue reading

On Stephen Law on Scientism

scientism It’s good to see philosophers taking scientism seriously, and not just using the term as a bogey word. Massimo Pigliucci and Maarten Boudry are editing a forthcoming volume on scientism (Total Science, University of Chicago Press) and some of the essays are appearing on the internet.

I’ll discuss here the draft chapter by Stephen Law (Heythrop College, University of London) who writes, discussing the proper scope of science:

stephen_law

As a philosopher, you might expect me both to want to carve out some intellectual territory for philosophers to occupy, and also to resist the thought that philosophical questions and problems are either non-questions and non-problems or else questions that will be answered and problems that will be solved, if at all, through an application of the scientific method. I won’t disappoint. However, while I acknowledge that there are limits to science, I will argue these limits typically offer little comfort to religious, New Age, and other folk looking for ways to immunize their beliefs against scientific refutation.

As that last sentence suggests, science has been so successful in generating knowledge that it can be threatening to other beliefs. Do other belief systems have an independent validity, in domains of knowledge that are simply not the business of science, or can a scientific approach prevail in all domains? As Law says, the desire to limit science often originates from a desire to indulge beliefs that derive from wishful thinking, without feeling any need to supply science-grade evidence to back them up.

Law discusses Stephen Gould’s proposal of “non-overlapping magesteria” of knowledge, of which science would be only one. In contrast, scientism is the wholesale rejection of NOMA and the declaration that knowledge is a unified whole, and that the basic ways of finding things out that we refer to as “science” apply universally.

Let’s also be clear that scientism is not the claim that science can answer all questions, it’s the claim that there are no independent “ways of knowing” that can answer questions that science cannot. It is easy to think of questions that are meaningful but which we will never be able to answer (I’ve previously given some examples, including: What did Julius Caesar eat on the day three days before his eighth birthday, and did he stroke a dog on that day?).

Law is sympathetic to much of scientism and I won’t address the many parts of his chapter with which I agree. I’ll focus only on two areas where Law dissents from scientism: Continue reading

Telling science from pseudoscience and the demarcation problem

demarcPhilosophers of Science have long puzzled over what they call “the” demarcation problem, of how to distinguish science from pseudoscience. In the early 20th Century the Logical Positivists proposed the verification principle, that a statement was meaningful and scientific only if it could be empirically verified. Karl Popper then proposed a similar idea, that a scientific idea is one that can be falsified.

There is a lot of truth in both proposals, but neither can be interpreted too narrowly. The problem is that no statement can be verified or falsified in isolation. Science constructs whole webs of ideas, and it is the whole construct that is then compared to empirical data, to be adjusted and improved as necessary. Further, a statement such as Newton’s law of gravity can never be verified in the general sense, all we can say is that it worked well enough — as part of the wider web of ideas — in the particular instance we tested. Nor is it straightforward to falsify such a law. If our overall model is inconsistent with an observation then we could indeed alter one of the laws; but we might also overcome the inconsistency by altering some other part of the overall model; or we might doubt the reliability of the observations. Continue reading

Lamenting the reburial of ancient bones

In 2015 ISIS captured the ancient city of Palmyra and proceeded to destroy ancient ruins that they regarded as pagan or polytheistic. The World Heritage Site monuments were typically 2000 years old. Did ISIS have a right to destroy them? Most of us would say no, and would lament the loss of a heritage that cannot be replaced.

In saying that we are being culture-ist. That is, we are placing the values of our culture above those of ISIS, who, after all, would regard their acts as virtuous and as mandated by the highest authority, namely their religion. I readily plead guilty to be unapologetically culturist.

This comparison might be considered inappropriate, but in Nature this week I read about a 12,600-yr-old skeleton, the “Anzick Child”, that had been passed to Native American groups for reburial. The article lists 12 other skeletons, all older than 8000 yrs, that have either been reburied or might be. Reburial here effectively means their permanent loss, since they would decay relatively quickly under normal burial conditions.

As a scientist I am saddened by the loss of irreplaceable material that could tell us much about the past history of humans. I would regard such remains as part of the common heritage of us all and am unhappy about one group destroying them in the same way that I am unhappy about a group taking it upon itself to destroy Palmyra or the Bamiyan Buddha statues. This is obviously very culturist of me, but then I’ve already pleaded guilty. Continue reading

Having abandoned Divine Command Theory around the age of 12, when I realised that I was an atheist, I then read John Stuart Mill at the impressionable age of 14 and instantly became a utilitarian. I remained so well into adulthood; it seemed obvious that morality was a matter of objective wrong and right, and that utilitarianism — the greatest good of the greatest number — was the way to determine such facts.

Of course I also became aware of the unresolved problems with utilitarianism: there is no way to assess what is “good” except by subjective judgement, and there is no way to aggregate over sentient creatures (should a mouse count equally to a human?) except, again, by subjective judgement. Both of those rather clash with the desired objectivity of the scheme.

Periodically I would try to fix these flaws, but never succeeded. Such mulling led me to the realisation that I didn’t actually know what moral language actually meant. “It is morally right that you do X”, can be re-phrased as “you ought to do X”, but what do those mean? I realised that I didn’t know, and had been proceeding all this time on the basis that what they meant was intuitively obvious and so didn’t need analysis.

But that’s not good enough if we’re trying to solve meta-ethics and understand the very foundations of morality. And so, I eventually arrived at the realisation that the only sensible meaning that can be attached to the moral claim “you ought to do X” is that: at least one human, likely including the speaker, will dislike it if you do not do X. Similarly, “It is morally right that you do X” becomes a declaration that the speaker will approve of you doing X and disapprove of you not doing X. Continue reading

Reductionism and Unity in Science

One problem encountered when physicists talk to philosophers of science is that we are, to quote George Bernard Shaw out of context, divided by a common language. A prime example concerns the word “reductionism”, which means different things to the two communities.

In the 20th Century the Logical Positivist philosophers were engaged in a highly normative program of specifying how they thought academic enquiry and science should be conducted. In 1961, Ernest Nagel published “The Structure of Science”, in which he discussed how high-level explanatory concepts (those applying to complex ensembles, and thus as used in biology or the social sciences) should be related to lower-level concepts (as used in physics). He proposed that theories at the different levels should be closely related and linked by explicit and tightly specified “bridge laws”. This idea is what philosophers call “inter-theoretic reductionism”, or just “reductionism”. It is a rather strong thesis about linkages between different levels of explanation in science.

To cut a long story short, Nagel’s conception does not work; nature is not like that. Amongst philosophers, Jerry Fodor has been influential in refuting Nagel’s reductionism as applied to many sciences. He called the sciences that cannot be Nagel-style reduced to lower-level descriptions the “special sciences”. This is a rather weird term to use since all sciences turn out to be “special sciences” (Nagel-style bridge-law reductionism does not always work even within fundamental particle physics, for which see below), but the term is a relic of the original presumption that a failure of Nagel-style reductionism would be the exception rather than the rule.

For the above reasons, philosophers of science generally maintain that “reductionism” (by which they mean the Nagel’s strong thesis) does not work, and on that they are right. They thus hold that physicists (who generally do espouse and defend a doctrine of reductionism) are naive in not realising that.

“The underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known, and the difficulty is only that the exact application of these laws leads to equations much too complicated to be soluble.”     — Paul Dirac, 1929 [1]

The problem is, the physicists’ conception of reductionism is very different. Physicists are, for the most part, blithely unaware of the above debate within philosophy, since the ethos of Nagel-style reductionism did not come from physics and was never a live issue within physics. Physicists have always been pragmatic and have adopted whatever works, whatever nature leads them to. Thus, where nature leads them to Nagel-style bridge laws physicists will readily adopt them, but on the whole nature is not like that.

The physicists’ conception of “reductionism” is instead what philosophers would call “supervenience physicalism”. This is a vastly weaker thesis than Nagel-style inter-theoretic reduction. The physicists’ thesis is ontological (about how the world is) in contrast to Nagel’s thesis which is epistemological (about how our ideas about the world should be). Continue reading

A “theology of science” debate with Tom McLeish

Last November I took part in a debate on science and theology at the invitation of the Keele University Institute of Liberal Arts and Sciences. My fellow speaker (I don’t want to call him an “opponent”) was Professor Tom McLeish of Durham University, a leading soft-matter physicist.

Tom McLeish portrait

Professor McLeish is a Christian who has written a book, newly out in paperback, Faith and Wisdom in Science. To prepare for the debate I ordered a copy for the library. My first indication that this wasn’t a typical science book was that it got shelved with books on Biblical exegesis, and I thus found myself wandering to a region of the library where I’d never previously been!

Tom McLeish book Faith and Wisdom in Science

I liked the book, one can learn a lot about the nature of science from it. Tom McLeish emphasizes that science is a fundamentally human enterprise with deep roots in our history. Science is not just a modern phenomenon, newly sprung on the world with The Enlightenment, but is a continuation of age-old human attempts to understand ourselves and our place in the universe. It should not be seen as a separate, arcane and primarily theoretical subject (as it is often badly taught in schools), but as human exploration.

As Professor McLeish explains, science does not accept that anything is outside of its purview. And neither does theology. If the claims of the Abrahamic religions are true then theology must infuse every aspect of our existence. Thus the oft-stated and politically-correct claim that science and theology operate in different domains and answer different questions is deeply unsatisfying both to scientists and to theologians.

With a foot in both camps, Professor McLeish sees this clearly. He thus talks, not about theology and science, but about a theology of science. His book sets out that vision.

My role in the debate was to present the alternative way of reconciling two idea-systems that both claim to be all-encompassing — and that is to play the atheistic curmudgeon and simply reject and excise theology entirely. Continue reading