What is Naturalism?

Estimated reading time: 9 minutes

Naturalism (1) is a philosophy or ontology (2), about the nature of reality, typically associated with atheism. Naturalism says there is only one world, the natural world, exhibiting patterns called the laws of nature (TBP156 – see Notes). These laws are discoverable by the methods of science and empirical investigation. Empirical evidence (3) is knowledge acquired by means of the senses, particularly by observation and experimentation. Naturalism affirms there is no separate realm of the supernatural, spiritual, or divine. There is no cosmic or transcendent purpose inherent in the universe or in human life (TBP207, 235, 381). We find traces of Naturalism in Buddhism (4), in the atomists of ancient Greece and Rome, and in Confucianism (5) (TBP242).

Sean Carroll introduced the term ‘Poetic Naturalism’ (6) in his 2016 book ‘The Big Picture: On the Origins of Life, Meaning and the Universe Itself ’.(7) Carroll is a theoretical physicist and Research Professor of Physics at Caltech, who blogs at Preposterous Universe.(8) Poetic Naturalism means there are many ways of talking about the world. We talk about ‘causes’ and ‘reasons why’ things happen, but those ideas
aren’t part of how nature works at its deepest levels. They are emergent phenomena – how we describe our everyday world (TBP159). Naturalists have disagreements about what they mean by naturalism. At one end of the naturalism spectrum are the ‘mad-dog’ eliminativist naturalists like Alex Rosenberg (9) (I arranged for Rosenberg to speak to Atheism UK at Conway Hall in 201210).

Rosenberg writes, in the ‘Atheists Guide to Reality’,(11) that “there is no moral difference between right and wrong, good or bad; there is no chance we have free will”.(12) Carroll summarises Rosenberg’s position as: “the world is just a bunch of particles”, “people are not conscious” and “there is no such thing as morality”. (13)
At the other end of the naturalism spectrum are naturalists such as Sam Harris14 who say that “science can be used to discover meaning and morality” (15) or there are “objective moral guidelines that tell you how to behave”(16). Carroll calls his ‘judicious middle ground’ (17) in
the ongoing naturalism debate, ‘poetic’ naturalism. Answering questions about morality and meaning, such as; ‘How do we go about deciding what is right and wrong?’ and ‘What is meaningful?’, is not the same as the way we discover what is true and false (18). Moral principles may be real (or at least as real as the rules of chess (19), but they are subjective, not objective – so oral realism20 is wrong (21). Carroll agrees with Sharon Street’s [not my wife!] Humean constructivism view, (22) that different people can construct different moral principles (TBP6524). Whitley Kaufman argues that Carroll has “not convincingly shown that morality is not objectively true within a naturalistic worldview”(23).

Why does the macroscopic world – the world of tables, chairs, people and planets and everything else, seem so different from the underlying microscopic fundamental physics? The microscopic ‘everyday’ world comprises four particles (up and down quarks, (24) neutrinos (25) and electrons (26), four forces (weak and strong nuclear (27), electromagnetism (28) and gravity (29), space-time (30) and the Higgs field (discovered in 2012) (31) The compatibility of the microscopic and macroscopic world can be explained by ‘emergence’. Emergent theories describe different kinds of things and concepts than more comprehensive theories from which they emerge(32).

‘Macroscopic world emerges from Microscopic world’ by SM Carroll, Source: https://goo.gl/vLrCOR 24.30 m



Frank Wilczek ( 33) (a N obel prize winner (34) in hi s book the ‘Lightness of Being’,35 combined Einstein’s general theory of relativity (36) with the Stand ard Model37 to give the ‘Core Theory’ of particles and forces.38 Carroll makes a bold statement: Core Theory describes “everything going on with in you, and me, and everything you see around you this minute. And it will continue to be accurat e, a thousand or a million years from now… hopefully by then we will have better, deeper concepts, but the concepts we’re using now will still be legitimate in the appropriate domain” (TBP2503).

The Microscopic ‘Everyday’ World: Four Particles, For Forces, Space-time, Higgs Field by SM Carroll, Source: https://goo.gl/vLrCOR 22.50 m

Carroll makes more bold statements about the Core Theory: The laws of physics underlying everyday life are the ‘Core Theory’ (TBP6960) which underlies “everything we witness in our everyday lives, including ourselves” (TBP3441) and some aspects of astrophysics (39) and cosmology (40) (TBP3014). “It seems overwhelmingly likely to be true, that the laws of physics underlying everyday life, are now completely known” (TBP2826).



The Core Theory rules out the possibility of souls (TBP2514). There can be no immaterial soul that could possibly survive the body. When we die, that’s the end of us; there is no life after death and no chance of being reincarnated into another life. The Core Theory also means that bending spoons with the power of the mind (TBP2455), and astrology (TBP172), are ruled out.

Could our universe have had a beginning without a ‘cause’? Our universe just popping into existence from nothing seems implausible as this would violate conservation of energy laws which say you cannot get energy where no energy exists (TBP3191). It’s wrong to say the universe comes from ‘nothing’ (TBP3183). In a peer-reviewed paper written by Carroll, one scenario for the formation of our universe, is the ‘Baby Universe’ hypothesis. In this idea, our observable universe evolved from a parent universe which was both eternal and empty (41). At the ‘Big Bang’, 13.8 billion years ago, our parent universe pinched off (a quantum fluctuation (42) a part of its spacetime; to form our ‘baby universe’. Baby universes start out small, with low entropy, (43) then they expand and cool, creating an arrow of time. (44) The universe inflated, generating a tremendous amount of energy, then over billions of years formed stars and galaxies (45).

The 2nd Law of Thermodynamics (46) states that the total entropy (‘disorder’) of a closed system never decreases, it stays constant or increases as time passes (TBP952). Entropy in the universe continually increases. If entropy or disorder is always increasing, how did the universe ever produce anything as complex as life on Earth? Carroll describes how the universe evolved, using a cup of coffee as an analogy. The universe started out very simple, like a cup of coffee with coffee on the bottom and cream floating on the coffee. The universe became complex and life emerged, like cream swirling and intermingling with the coffee, creating complex tendrils of coffee and cream. Finally, in the far future, the universe will become simple again, devoid of stars and galaxies – the cream and coffee become fully mixed together – making the coffee-cream system simple again (TBP3537).


Naturalism has begun to explain the origins of life. How did these early lifeforms make cells? Fatty acids (47) have a water loving (hydrophilic) head and a water avoiding (hydrophobic) hydrocarbon tail (TBP4026). Two fatty acids bond with glycerol48 and phosphate
to form membrane phospholipid bilayers – which can spontaneously form cells. The cell is needed to protect DNA49 (deoxyribonucleic acid), proteins and metabolic pathways etc. from the external environment (TBP3963).

The ‘Core Theory’ by F. Wilczek Source: https://goo.gl/YeyqZ5



How was the first life on Earth powered? One theory is that deep sea alkaline hydrothermal vents (50) attracted positively charged protons51 (TBP4124). The protons were formed from neutral hydrogen atoms by loss of the negatively charged electron, leaving a positively charged proton in the nucleus. The repulsion between protons produced a proton-motive force (TBP3876). When protons are pumped through ATP Synthase52 protein, ATP53 (Adenosine triphosphate) is formed. In bacteria, animals and plants, ATP is the main source of energy, which is  needed to build up or break down molecules (54).

In photosynthesis55 plants use photons of light from the sun to strip off electrons from water molecules. Water splits to give positively  charged protons and oxygen (TBP3861). The proton-motive force pumps protons through ATP Synthase, which is embedded in the phospholipid bilayer membrane. The proton pump provides energy for ATP molecules to be manufactured from ADP56 (Adenosine  diphosphate) and phosphate (TBP3861) (57).

Today the Central Dogma of Biology58 states that DNA stores information as genetic code. m-RNA59 (messenger Ribonucleic acid) then copies this information to assemble proteins. When life started, how was DNA made? Maybe RNA came before DNA (RNA World hypothesis60), in evolutionary terms, since RNA can both store information and make proteins (TBP4211). Life is not a substance, nor a spirit or élan vital (61) (life force), it’s a process (TBP3493).

If there were a supernatural element that played a role in our everyday life in some noticeable way, it’s very, very likely we would have noticed it. The late Victor Stenger (62) has pointed out that prayers would work, but they don’t (63). It just seems weird that this kind of thing would be so crucial and yet so difficult to notice in any controlled scientific way (64). We should all try to guard against our individual cognitive biases (65), the things we want to be true. The  existence of life after death, for example, might be wonderful. Many people have a cognitive bias in favour of that. And yet I don’t think that is true. The best we can do is try to be hones (66).

“Life” and “consciousness” do not denote essences distinct from matter; they are ways of talking about phenomena that emerge from the  interplay of extraordinarily complex systems. Purpose and meaning in life arise through human acts of creation, rather than being derived from anything outside ourselves. Naturalism is a philosophy of unity and patterns, describing all of reality as a seamless web (TBP241). What happened at the big bang or at the start of life on Earth? We don’t really know! There are lots of theories and we are still working that out. That’s the strength of science and naturalism. The willingness to say we don’t know everything. We’ve got to figure lots out. We walk a tightrope of epistemic humility. It’s easy to say ‘we know everything’ or ‘we know nothing’. What is harder to say is ‘we know some things, and here is the dividing line between what we know and what we don’t know’ (67).

Central Dogma of Biology: DNA makes RNA makes Protein Source: https://goo.gl/ml2StZ Location: TBP4194 Image source: https://goo.gl/4Vg4pV



TBP followed by numbers in brackets is the location in S.M Carroll (2016), The Big Picture: On the Origins of Life, Meaning and the Universe Itself, Oneworld Publications, Kindle edition. All images and links accessed February 2017.

1. https://en.wikipedia.org/wiki/Naturalism_(philosophy)
2. https://simple.wikipedia.org/wiki/Ontology
3. https://en.wikipedia.org/wiki/Empirical_evidence
4. https://simple.wikipedia.org/wiki/Buddhism
5. https://simple.wikipedia.org/wiki/Confucianism
6. https://en.wikipedia.org/wiki/Poetic_naturalism
7. S.M. Carroll (2016). The Big Picture: On the Origins of Life,
Meaning and the Universe Itself, Oneworld Publications,
8. S.M. Carroll, Preposterous Universe website, http://www.
9. http://rationallyspeakingpodcast.org/show/rs-162-sean-
carroll-on-poetic-naturalism.html 5:13m
10. https://www.youtube.com/watch?v=zoH4YBPbx5Y
11. http://books.wwnorton.com/books/detail.aspx?ID=22355
12. A. Rosenberg. The Atheist Guide to Reality: Enjoying life
with illusions, (2011), WW Norton, page 3
13. http://rationallyspeakingpodcast.org/show/rs-162-sean-
carroll-on-poetic-naturalism.html 10:02m
14. http://rationallyspeakingpodcast.org/show/rs-162-sean-
carroll-on-poetic-naturalism.html 13:33m
15. https://www.scientificamerican.com/article/godless-universe-
16. http://rationallyspeakingpodcast.org/show/rs-162-sean-
carroll-on-poetic-naturalism.html 4:22m
17. https://www.scientificamerican.com/article/godless-universe-
18. https://www.scientificamerican.com/article/godless-universe-
19. http://rationallyspeakingpodcast.org/show/rs-162-sean-
carroll-on-poetic-naturalism.html 17:32m
20. http://www.philosophybasics.com/branch_moral_
21. http://rationallyspeakingpodcast.org/show/rs-162-sean-
carroll-on-poetic-naturalism.html 12:37m
22. http://rationallyspeakingpodcast.org/show/rs-162-sean-
carroll-on-poetic-naturalism.html 18:43m
23. http://onlinelibrary.wiley.com/doi/10.1111/zygo.12325/full
24. https://simple.wikipedia.org/wiki/Quark
25. https://simple.wikipedia.org/wiki/Neutrino
26. https://simple.wikipedia.org/wiki/Electron
27. https://simple.wikipedia.org/wiki/Strong_interaction
28. https://simple.wikipedia.org/wiki/Electromagnetism
29. https://simple.wikipedia.org/wiki/Gravity
30. https://simple.wikipedia.org/wiki/Space-time
31. https://simple.wikipedia.org/wiki/Higgs_field
32. S.M. Carroll,Talks at Google, May 16 2016, https://www.
youtube.com/watch?v=x26a-ztpQs8&t=2292s 22:50m
33. F. Wilczek, website http://frankwilczek.com/
34. https://www.nobelprize.org/nobel_prizes/physics/laureates/
35. F. Wilczek (2009). The Lightness of Being: Big
Questions, Real Answers, Penguin, https://
36. https://simple.wikipedia.org/wiki/General_relativity
37. https://simple.wikipedia.org/wiki/Standard_Model
38. http://frankwilczek.com/2014/coreTheory.pdf
39. https://simple.wikipedia.org/wiki/Astrophysics
40. https://simple.wikipedia.org/wiki/Cosmology
41. S.M. Carroll and J. Chen, 2004, Spontaneous Inflation and
the Origin of the Arrow of Time [online], https://arxiv.
42. https://simple.wikipedia.org/wiki/Quantum_fluctuation
43. https://simple.wikipedia.org/wiki/Entropy
44. S.M. Carroll, 1st Gifford lecture in Natural
Theology, Oct 2016, Uni Glasgow, http://
45. https://www.youtube.com/watch?v=X0qKZqPy9T8
Carroll debates William Lane-Craig
46. https://simple.wikipedia.org/wiki/
47. https://simple.wikipedia.org/wiki/Fatty_acid
48. https://simple.wikipedia.org/wiki/Glycerol
49. https://simple.wikipedia.org/wiki/DNA
50. https://en.wikipedia.org/wiki/Hydrothermal_vent
51. https://simple.wikipedia.org/wiki/Proton
52. https://simple.wikipedia.org/wiki/ATP_synthase
53. https://simple.wikipedia.org/wiki/
54. S.M. Carroll, 4th Gifford lecture in Natural Theology, Oct
2016, Uni Glasgow, https://www.youtube.com/watch?v=GbmdtcQZUsg&
feature=youtu.be 23:00m
55. https://simple.wikipedia.org/wiki/Photosynthesis
56. https://simple.wikipedia.org/wiki/Adenosine_diphosphate
57. S.M. Carroll, 4th Gifford lecture in Natural Theology, Oct
2016, Uni Glasgow, https://www.youtube.com/watch?v=GbmdtcQZUsg&
feature=youtu.be 27:18m
58. https://simple.wikipedia.org/wiki/
59. https://simple.wikipedia.org/wiki/RNA#Messenger_RNA
60. https://simple.wikipedia.org/wiki/
61. https://en.wikipedia.org/wiki/%C3%89lan_vital
62. https://simple.wikipedia.org/wiki/Victor_J._Stenger
63. H. Benson et al, ‘Largest Study of Third-Party Prayer
Suggests Such Prayer Not Effective In Reducing Complications
Following Heart Surgery’, Uni Harvard, Boston,
Mar 2006. http://web.med.harvard.edu/sites/RELEASES/
64. https://www.scientificamerican.com/article/godless-universe-
65. https://simple.wikipedia.org/wiki/Cognitive_bias
66. https://www.scientificamerican.com/article/godless-universe-
67. S.M. Carroll, 5th Gifford lecture in Natural Theology,
Oct 2016, Univ. Glasgow, https://www.youtube.com/
watch?v=VNdCYYQsZGA 51:37m

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