What the physicists actually said

Verified quotations on cosmic fine-tuning from the physicists and astronomers who study it, with each speaker's own position on God and the conclusion each one actually drew.

Most of the physicists who say the universe is fine-tuned are not Christians, and most of them draw a conclusion this site rejects.  That is the honest and the more persuasive way to present them.

Apologetics collects quotations about fine-tuning the way a magpie collects foil, and the result is usually a wall of impressive names with the awkward parts trimmed off.  This page does the opposite.  Every quotation below is given with the speaker's own position on God and with the conclusion that speaker actually drew — which, in most cases, is not ours.

Why include quotes that cut against us?  Because the argument they support is stronger that way.  "Twenty scientists agree the universe was designed" is false and any reader can check it.  "Twenty scientists, most of them atheists and agnostics, agree that the constants sit in narrow life-permitting windows, and disagree only about what explains it" is true, checkable, and much harder to dismiss.  The data is not in dispute.  The interpretation is.

How to read the table

Leaning is the speaker's own stated position, from their own words where one exists, not a label assigned by this site or inherited from an apologetics source.  Where a position is genuinely unclear or self-described as unclassifiable, the table says so rather than forcing a category.

Concludes is what that person says explains the fine-tuning.  It is a separate question from their religious position and the two do not always track.  Several theists on this list decline to treat fine-tuning as proof of anything, and at least one non-theist rejects both God and the multiverse.

Verified means the wording was checked character by character against the primary source and the URL was fetched.  Quotations that could not be verified are not in the table at all — they are listed at the bottom under what could not be confirmed, so that nobody rebuilds them from this page.

"Not stated" is used, and used often.  Of roughly fifty people surveyed for this page, fifteen have no religious self-identification that can be traced to a primary source at all — including Brandon Carter, Alan Guth, Andrei Linde, Alexander Vilenkin, Lee Smolin, Edward Witten, Paul Steinhardt, Max Tegmark and Fred Adams.  Apologetics sites confidently label several of them atheists; atheist sites do the same.  Neither can point to the person saying it.  Where that is the situation, this page says so rather than guessing, and those people are simply not given a leaning in the table.

The quotations

Person Field Leaning Quotation Concludes
Fred Hoyle (1981) Astronomer; discovered stellar nucleosynthesis Rejected theism; argued for a cosmic superintellect and panspermia "A common sense interpretation of the facts suggests that a superintellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question."1 An intelligence within the cosmos — not a transcendent creator. He defended steady-state cosmology against the big bang to the end of his life.
Paul Davies (2003) Theoretical physicist, Arizona State Neither theist nor atheist, by his own description "There is now broad agreement among physicists and cosmologists that the universe is in several respects 'fine-tuned' for life… So the conclusion is not so much that the universe is fine-tuned for life; rather, it is fine-tuned for the essential building blocks and environments that life requires. Such fine-tuning is a necessary, but by no means sufficient, condition for biogenesis."2 A "life principle" built into nature. The same paper's abstract says it examines and criticises the claim that life is "written into" the laws.
Martin Rees (2007) Astronomer Royal Non-believer; his own formula is "a practicing Christian, but not a believing one"3 "If our existence — or, indeed, the existence of any 'interesting' universe — depends on a seemingly special cosmic recipe, how should we react? There seem three lines to take: we can dismiss it as happenstance, we can invoke 'providence', or we can conjecture that our universe is a specially favoured domain in a still vaster multiverse."4 The multiverse. He rejects happenstance, reports providence without endorsing it, and chooses the third. In 2018 he also softened one of his own six numbers, concluding that the fluctuation amplitude is "not particularly finely tuned."5
Stephen Hawking (1988) Theoretical physicist, Cambridge Atheist "The remarkable fact is that the values of these numbers seem to have been very finely adjusted to make possible the development of life… One can take this either as evidence of a divine purpose in Creation and the choice of the laws of science or as support for the strong anthropic principle."6 Names divine purpose as one of exactly two live readings, endorses neither there, and takes the multiverse later in The Grand Design.
Roger Penrose (1989) Mathematical physicist, Oxford; Nobel laureate Atheist by his own description, though a soft one — he avoids the word "God" and allows it "in a more metaphorical sense." Also a committed mathematical Platonist On the precision of the initial state: one part in 1010123.[penrose-1989] And on its meaning: "What about the anthropic principle? Again, this is virtually no help to us whatever in resolving our conundrum."7 A new law of physics — the Weyl Curvature Hypothesis. He rejects the anthropic reading of his own number in print.
Freeman Dyson (1979) Mathematical physicist, Princeton Non-traditional. His own words: "a practicing Christian but not a believing Christian." Doctrinally a self-described Socinian who denied the Trinity8 "The more I examine the universe and the details of its architecture, the more evidence I find that the universe in some sense must have known that we were coming."9 Explicitly not proof: "I do not claim that the architecture of the universe proves the existence of God. I claim only that the architecture of the universe is consistent with the hypothesis that mind plays an essential role in its functioning."9
Lee Smolin (2012) Theoretical physicist; loop quantum gravity Not stated — no primary self-description found "Embedded within the laws of physics are roughly 30 numbers… it's plausible that changing just a few of these parameters would have resulted in a starkly different universe: one without stars or galaxies and even without a diversity of stable atoms."10 Cosmological natural selection. He rejects both God and the anthropic multiverse as unscientific — which makes him the most independent witness on this page.
Charles Townes (2005) Physicist; Nobel laureate for the laser Self-described "very progressive" Protestant. He called anti-evolutionism "stupid" and Genesis 1 "an analogy" — a disclosure this site owes its readers "This is a very special universe: it's remarkable that it came out just this way. If the laws of physics weren't just the way they are, we couldn't be here at all."11 Design — including design working through evolution. Readers of this site should know he rejects its position on origins.
Alexander Vilenkin Cosmologist, Tufts Not stated — no primary self-description found "Why do the constants of Nature take the particular values that they are observed to have in our universe? It certainly appears that the constants have not been selected at random."12 Anthropic selection within an inflationary multiverse.
Bernard Carr and Martin Rees (1979) Astrophysicists Rees as above; Carr is non-traditional — a Christian with Buddhist sympathies who holds Mind to be fundamental and rejects intelligent design "Even if all apparently anthropic coincidences could be explained in this way, it would still be remarkable that the relationships dictated by physical theory happened also to be those propitious for life."13 Nothing theistic. The same paper calls the anthropic principle "entirely post hoc" and notes it has never made a prediction.13
Fred Adams (2019) Astrophysicist, Michigan Not stated — no primary self-description found "Extreme hierarchies are required for any universe to be viable."14 And, against: "Tuning a radio thus requires far more precision than tuning a universe."14 No design. The most rigorous skeptical survey in the field, and the one apologetics most needs to answer.
Geraint Lewis (2016) Astrophysicist, Sydney Not a theist Co-author of the standard book on fine-tuning, agreeing with his Christian co-author on every number. The multiverse. His stated reasons against theism are the problem of evil, the evolutionary origin of moral intuitions, and "explaining a little by supposing a lot."15
Luke Barnes (2015) Astrophysicist, Western Sydney Christian "There is no 'diproton disaster'."16 Theism — argued as a rival to naturalism rather than to science. Included here because he published the refutation of apologetics' favourite fine-tuning example.
Christopher Hitchens (2009) Journalist and polemicist Atheist; self-described "antitheist"17 In the film Collision: "which is the best argument you've yet come up against from the other side? And I think every one of us picks the fine-tuning one — as the most intriguing… But even though it doesn't prove design, doesn't prove a designer, could all have happened without it, you have to spend time thinking about it, working on it."18 Rejects the inference, citing cosmic waste and cruelty. He never invokes the multiverse — in his debate with Craig, every mention of it is Craig's. Stopping this quote at "most intriguing" inverts his meaning.
John Leslie (1989) Philosopher, Guelph Non-traditional. Believes in "a reality I call God," defined as an impersonal creative principle — "not an almighty person but an abstract Creative Force"19 "Fine tuning is evidence, genuine evidence, of the following fact: that God is real, and/or there are many and varied universes."19 Explicitly disjunctive — God and/or a multiverse, both live. His famous firing-squad analogy uses fifty sharpshooters; the "144 marksmen" version everyone quotes is Swinburne's retelling. Citing him as a witness for a personal Creator misrepresents the very book being cited.
Peter Millican (2016) Philosopher, Oxford; Hume scholar Former Anglican, now a non-believer — "my theism was evaporating… Acknowledging that I could no longer call myself a Christian was a serious personal ordeal"20 "What's unusual about the fine-tuning argument is that it has the right kind of structure to deliver a strong result… it's clearly appealing to science rather than appealing to ignorance." And in print: "I am convinced that it is significantly better than most atheist philosophers seem to think."20 Does not find it persuasive — but refuses the strongest skeptical moves, calls the multiverse escape "metaphysically extravagant," and argues the argument, taken seriously, points against an infinite God and against the exclusive truth of any one religion.

What this table shows

Sixteen rows covering seventeen people.  Six reject God outright.  Five hold positions that fit neither "theist" nor "atheist" — a cosmic superintellect, a Socinian God, an impersonal creative principle, a self-described neither, and Carr's Christian-Buddhist synthesis.  Three have no traceable self-description at all, which is itself the point of the leaning column.  Two are Christians in the ordinary sense — Townes and Barnes — and Barnes is on the list for refuting a fine-tuning argument.  Rees appears twice.

Not one of them disputes that the constants sit in narrow windows.  Every disagreement is about what explains it: a multiverse, a deeper law not yet found, cosmological natural selection, a cosmic intelligence, a life principle, or God.

That is the real shape of this debate, and it is worth more to state it accurately than to assemble a jury that does not exist.

Context warnings

Four of these quotations are routinely used in ways their authors would reject.  If this site ever uses them, it uses them with the qualification attached.

Hoyle never became a theist.  His "superintellect" is an intelligence within or coextensive with the cosmos, not a creator.  Two pages before the famous sentence he writes of "an enormous intelligence abroad in the universe," and his 1983 book develops that idea rather than theism.  He also called the big bang a religious position and defended the steady-state model to the end.  Presenting him as a witness who came round is dishonest, and easily caught.

Rees offers the theistic reading only to set it aside.  In Just Six Numbers he puts the same set of options and answers them:  "Is this tuning just a brute fact, a coincidence?  Or is it the providence of a benign Creator?  I take the view that it is neither."  (That wording is corroborated by an author-bylined extract but has not been checked against a printed copy, which is why the table quotes the 2007 Cambridge chapter instead.)  Quoting his statement of the options without his answer misrepresents him.

Davies is arguing against a stronger version of the claim, not for it.  His paper's abstract states that it examines and criticises the idea that life is "written into" the laws.  His concession — fine-tuning is for life's building blocks, and is necessary but nowhere near sufficient — is more useful stated in full than trimmed.

Dawkins and Hitchens did not concede the argument.  Both singled it out as the strongest argument on the other side, and both rejected it.  Dawkins' reported full sentence includes "still a very, very bad argument."  Reporting the first half alone is the kind of thing that costs a reader's trust permanently — and note that the Dawkins remark itself sits in the unverified list below, because no primary venue for it has been confirmed.

Could not be verified

These circulate widely, including in this site's own research notes.  None of them appear in the table above, and none should be used until someone checks a primary copy.

  • Leonard Susskind's "elephant in the room" passage. Attributed to The Cosmic Landscape, usually dated 2008 although the book is 2005. No primary copy could be reached; every archive.org loan was checked out. The circulating transcription contains an obvious typo, which indicates it has passed through at least one relay.
  • Susskind's New Scientist exchange with Amanda Gefter — "we will be hard pressed to answer the ID critics." The underlying interview is real (17 December 2005) but the version in circulation is relayed through a blogger who editorialises inside the quotation.
  • Vilenkin's "about 30 constants of nature" remark. Traced only to an advocacy site quoting a video. Smolin's statement in the table above makes the same point, is verified, and comes from a better witness.
  • The longer, bracketed version of the Hitchens quotation that circulates on apologetics sites. The film passage itself is now verified (see the table), but the circulating text originates from a 2012 blog transcript with editorial insertions, framed as an admission "that there IS evidence for the existence of God" — which is not what he said. Cite the film at 1:24:20, not the blog.
  • The Dawkins "best one going / very, very bad argument" remark. The wording circulates consistently and is almost certainly genuine, but no interview, date or medium has been confirmed, so it does not appear in the table.
  • Exact print page numbers for Hawking, Penrose and Rees. Content and chapter are confirmed for all three; the page numbers in general circulation are not independently confirmed and three different pages circulate for Penrose.

Sources

  1. 1.

    Hoyle, Fred.  “The Universe: Past and Present Reflections.”  Engineering and Science 45(2):8–12.  Nov 1981.  Page 12:  The closing paragraph.  An essay by the astronomer Fred Hoyle, who never became a theist.  Its closing paragraph holds his remark that a superintellect has monkeyed with physics, chemistry and biology. ↩

  2. 2.

    Davies, Paul C. W.  “How bio-friendly is the universe?”  International Journal of Astrobiology 2(2):115–120.  2003.  An essay by a theoretical physicist at Arizona State that examines and criticises the claim that life is written into the laws of nature.  It concedes that the universe is fine-tuned for life's building blocks and environments, which is necessary but by no means sufficient for life to start. ↩

  3. 3.

    Klein, Stefan.  We Are All Stardust.  The Experiment.  Translated by Ross Benjamin.  2015.  Pages 10–11:  Rees is asked whether he can believe what is preached in church:  “No.  I know that we don't yet even understand the hydrogen atom — so how could I believe in dogmas?  I'm a practicing Christian, but not a believing one.”  A book of interviews with scientists, including Martin Rees.  The English wording is a translation of the 2010 German edition.  The phrase unbelieving Anglican, widely attributed to Rees, could not be traced to him at all. ↩

  4. 4.

    Rees, Martin J.  “Cosmology and the multiverse.”  Universe or Multiverse?, 57–75.  Cambridge University Press.  Edited by Bernard Carr.  2007.  Page 59.  Chapter 4 of an edited book, by the Astronomer Royal.  It is used in preference to the more famous recipe-for-a-universe passage in Just Six Numbers (1999), whose wording is corroborated only by an author-bylined web extract and whose usual page number could not be confirmed against any print copy. ↩

  5. 5.

    Livio, Mario, and Martin J. Rees.  Fine-Tuning, Complexity, and Life in the Multiverse.  2018.  On the fluctuation amplitude Q, they conclude that it.  “should best be between 10-6 and 10-4, and therefore not particularly finely tuned.”  A chapter by an astrophysicist and the Astronomer Royal.  Rees, who once listed the fluctuation amplitude among six fine-tuned constants, here softens that claim. ↩

  6. 6.

    Hawking, Stephen W.  A Brief History of Time: From the Big Bang to Black Holes.  Bantam.  1988.  Chapter 8:  The chapter is titled The Origin and Fate of the Universe.  It is commonly cited as p. 125; the chapter is confirmed, the print page is not.  A popular book on cosmology by the Cambridge theoretical physicist, cited for the passage on the finely adjusted values of the constants of nature. ↩

  7. 7.

    Penrose, Roger.  “Before the Big Bang: An Outrageous New Perspective and its Implications for Particle Physics.”  Proceedings of EPAC 2006, 2759–2763.  2006.  A conference paper (THESPA01, Edinburgh) in which Penrose argues that the Second Law of thermodynamics makes the universe's starting state extraordinarily special.  He rejects the anthropic principle as an explanation of that number, in his own words, and proposes a new law, the Weyl Curvature Hypothesis. ↩

  8. 8.

    Dyson, Freeman J.  “Science & Religion: No Ends in Sight.”  New York Review of Books.  Mar 28, 2002.  An essay in which Dyson adopted the label Socinian, a finite, growing, non-omniscient God immanent in the universe, and denied the Trinity. ↩

  9. 9.

    Dyson, Freeman J.  Disturbing the Universe.  Harper & Row.  1979.  Pages 250–251.  A memoir and set of essays by the Princeton mathematical physicist, cited for his remark that the universe in some sense must have known that we were coming. ↩

    1. 9a.

      “Being a scientist, trained in the habits of thought and language of the twentieth century rather than the eighteenth, I do not claim that the architecture of the universe proves the existence of God.  I claim only that the architecture of the universe is consistent with the hypothesis that mind plays an essential role in its functioning.” ↩

  10. 10.

    Smolin, Lee.  “Scientific Approaches to the Fine-Tuning Problem.”  NOVA.  PBS.  Dec 2012.  A web essay by a theoretical physicist who proposes cosmological natural selection and rejects both God and the anthropic multiverse as unscientific. ↩

  11. 11.

    Townes, Charles.  “Explore as much as we can.”  UC Berkeley News.  Jun 17, 2005.  An interview with the Nobel laureate for the laser, a self-described progressive Protestant. ↩

  12. 12.

    Vilenkin, Alexander.  “Predictions from Quantum Cosmology.”  Physical Review Letters 74:846.  1995.  A physics paper by the Tufts cosmologist on why the constants take the values they do.  The widely quoted 123 decimal places figure is from Tegmark's half of the joint Vilenkin-Tegmark Scientific American article of 19 July 2011, not Vilenkin's, and is often misattributed. ↩

  13. 13.

    Carr, Bernard J., and Martin J. Rees.  “The anthropic principle and the structure of the physical world.”  Nature 278:605–612.  Apr 12, 1979.  Page 612:  The closing sentence.  A long paper in Nature, the founding 1979 study of the anthropic principle, by two astrophysicists. ↩

    1. 13a.

      The same paper describes the anthropic principle as.  “entirely post hoc”. ↩

  14. 14.

    Adams, Fred C.  “The Degree of Fine-Tuning in our Universe — and Others.”  Physics Reports 807:1–111.  2019.  A long review of how far the constants of physics and the cosmological parameters can be varied before stars, planets and life no longer form.  The author is an astrophysicist at Michigan who works through each parameter and finds it has a wide range, so the page treats it as the most rigorous skeptical survey of the field. ↩

    1. 14a.

      Adams writes:  “Given that the concept of fine-tuning evokes the image of tuning the dials of a radio…  Tuning a radio thus requires far more precision than tuning a universe.” ↩

  15. 15.

    Lewis, Geraint F., and Luke A. Barnes.  A Fortunate Universe: Life in a Finely Tuned Cosmos.  Cambridge University Press.  2016.  A book for general readers by an astrophysicist who is not a theist and one who is a Christian, both then at Sydney.  They agree on every number in it and divide over the conclusion in the last chapter, which is why this page uses it.

    1. 15a.

      Lewis, in the concluding chapter:  “I would expect a morally perfect being to create a morally perfect universe, or at least the best universe available…  Still, the argument seems to be explaining a little by supposing a lot.” ↩

  16. 16.

    Barnes, Luke A.  “Binding the Diproton in Stars: Anthropic Limits on the Strength of Gravity.”  Journal of Cosmology and Astroparticle Physics 12:050.  2015.  A calculation of the stars that would form in a universe where the diproton, a nucleus of two protons, is bound.  It is the published refutation, by a Christian physicist, of apologetics' favourite fine-tuning example. ↩

  17. 17.

    Hitchens, Christopher.  God Is Not Great.  Twelve.  2007.  Page 102:  Hitchens defines antitheism as.  “the view that we ought to be glad that none of the religious myths has any truth to it, or in it.”  A polemic against religion.  It never mentions fine-tuning at all, and its design chapter is entirely biological. ↩

  18. 18.

    Doane, Darren.  Collision: Christopher Hitchens vs. Douglas Wilson.  2009.  At 1:24:20–1:24:53:  Wording from machine transcription; re-check by ear before treating any clause as exactly verbatim.  A documentary film of the debate tour of the atheist writer Christopher Hitchens and the pastor Douglas Wilson, directed by Darren Doane.  In his 2009 debate with William Lane Craig, Hitchens denied the description outright: This is not fine tuning, ladies and gentlemen. ↩

  19. 19.

    Leslie, John.  Universes.  Routledge.  1989.  Page 198.  Page 204:  Restated here.  A philosophy book on fine-tuning by a Guelph philosopher whose God is an impersonal creative principle rather than a person. ↩

    1. 19a.

      Page 2:  Neoplatonism's God, in Leslie's words:  “is then not an almighty person but an abstract Creative Force…  To be more specific, Neoplatonism's God is the world's creative ethical requiredness.”  Same page:  “this book shows no interest in the kind of God who designs the structures of individual organisms.”  Page 173:  “Can it be right, however, for a Neoplatonist to talk of a Design Argument when belief in a Designer has been abandoned?”  In a 2025 interview in Religious Studies he adds:  “Tegmark hasn't given us a viable alternative to God for explaining the fine tuning.” ↩

  20. 20.

    Millican, Peter.  “Defending the Common-Core/Diversity Dilemma.”  European Journal for Philosophy of Religion 9(3):81–106.  2017.  Pages 82–83.  A reply by an Oxford philosopher and Hume scholar to critics of his paper with Branden Thornhill-Miller.  He says he does not find the fine-tuning argument persuasive, but defends it as rationally respectable. ↩

    1. 20a.

      Page 87:  “I personally do not find the Fine Tuning Argument persuasive, but I am convinced that it is significantly better than most atheist philosophers seem to think (as long as its conclusion is, indeed, suitably restricted).”  The spoken quote on the page is from his 2016 Unbelievable? debate with Robin Collins (machine transcription).  The metaphysically extravagant verdict on the multiverse escape is from Thornhill-Miller and Millican, European Journal for Philosophy of Religion 7, no. 1 (2015), p. 47. ↩

  21. 21.

    Penrose, Roger.  The Emperor's New Mind.  Oxford University Press.  1989.  Chapter 7:  The chapter is titled How special was the Big Bang?  A book by the Oxford mathematical physicist.  Its chapter 7 gives the one part in 1010123^ figure for the precision of the universe's initial state.  The original technical treatment is Penrose, Singularities and time-asymmetry, in General Relativity: An Einstein Centenary Survey, ed. Hawking and Israel, Cambridge University Press, 1979, pp. 581–638.