The evolutionary argument against moral realism

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. “It is morally right that you do X” then 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

Hume’s subjective morality: Making value judgements about value judgements

One theme of this blog has been my arguments — as a disciple of Hume — that morality is subjective, thus rejecting that idea that moral claims can be assigned truth values and that they are independent of human judgement on the matter. (For example, see my posts: Six reasons why objective morality is nonsense and Science can answer morality questions.)

This idea, though, often meets strong intuitive resistance. A common complaint is that, if moral claims are “merely” people’s opinions, then one cannot say that the morals of a virtuous man, living a blameless life and esteemed by his fellows, are any better than those of a delinquent mass murderer.

The suggestion is that, if morals are human sentiments, rather than being objective statements of fact, then we must value everyone’s sentiments and morals equally.

This, however, is a non-sequitur. There is nothing to stop us making value judgements about value judgements. Indeed we commonly do so. There is nothing at all preventing us from respecting and lauding someone we regard as a moral paragon, or from deprecating someone we regard as a delinquent.

Stated like this the point is perhaps obvious, yet many objections to the idea that morality is subjective amount to the idea that one needs permission to make value judgements, permission that can only come from a reference to an objective standard, and that in the absence of such a standard one must regard everyone’s opinion as “equally valid”. 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

On explanations and causality within physics

I recently watched a video by philosophers Massimo Pigliucci (City University of New York) and Daniel Kaufman (Missouri State University) discussing differences in styles of explanation between the natural sciences and the social sciences. There’s a lot in the video that I agree with, but I want to dissent on one issue. That is, I don’t agree that causality is as central to explanations within physics as the video suggests, and thus the differences with the social sciences are less pronounced than suggested. (Though, having said that, I do agree that there is one very big difference in that biological entities exhibit purpose and intention, whereas physical entities do not.)

Pigliucci and Kaufman suggest that “explanations” within the physical sciences are typically in terms of causation, and thus are of the form of pointing to antecedent causal events that are sufficient to explain subsequent events. They also discuss “laws of physics” as being “widely generalisable causal relations”.

I would instead say that physical laws are often not about causes and are just descriptive. They would thus be “widely generalisable descriptive relations”. The meaning of “explanation” within physics is also much broader than just causal explanations. More generally, “explanations” are linkages between descriptions of different aspects of the system. All systems, simple or complex, can be (partially) described in different ways, and if we show how those descriptions link together then we “explain”. Continue reading

Once more on theory and law in science

It is well known that the popular usage of “theory” as meaning an unproven idea differs from how scientists use the word. And that allows creationists to wreak all sorts of “only a theory” mischief.

Defenders of science, however, often over-react to this charge by asserting that, in science, “theory” means a well-tested and well-evidenced account. For example the US National Academy of Sciences makes a well-meaning but wrong statement, defining:

Theory: In science, a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.

In fact, scientists use the word to mean merely “explanation”, or perhaps “set of explanatory ideas”, and it carries little connotation either way as to whether that explanation is tested or proven. For example “string theory” is highly speculative and unproven. Similarly, we still talk about Newton’s theory of gravity even though we know that it is only approximately correct and that it has been superseded by Einstein’s theories. Continue reading

I get taken to task by Jeffery Jay Lowder over the Cosmological Argument

Jeffery Jay Lowder, founder of Internet Infidels, has objected to a post of mine, William Lane Craig’s eight Special-Pleading arguments for God’s existence, that was in turn a reply to an article by theologian William Lane Craig in Philosophy Now. Craig’s article presented a number of arguments for the existence of God, including the “cosmological argument”.

Lowder’s charge is that I didn’t take a serious enough approach to Craig’s article, and didn’t respond carefully to how Craig had laid out his argument. I accept that my article was dismissive in tone, and, rather than giving a thorough examination of each of Craig’s points, I attempted to highlight a “special pleading” element running through all of them. But, I still regard my post as being fair; essentially, I regard the whole cosmological argument as being one big whopper of special pleading. Continue reading