The universe is finely tuned for life

Jonathan Sarfati

1997, updated 2015

Strong evidence for a Designer comes from the fine-tuning of the universal constants and the solar system, e.g.

Former atheist Sir Fred Hoyle states, ‘commonsense interpretation of the facts is that a super-intelligence has monkeyed with physics, as well as chemistry and biology, and that there are no blind forces in nature.’

Objection 1: (Barrow & Tipler1) We should not be surprised that we do not observe features of the universe incompatible with our own existence, for if features were incompatible, we would not be here to notice it, so no explanation is needed.

However, as Craig pointed out (in turn borrowing from philosopher John Leslie), it does not follow that we should not be surprised that we do observe features compatible with our existence; we still need an explanation.2

By analogy, if you were dragged before a trained firing squad, and they fired and missed:

  1. You should not be surprised that you do not observe that you are dead, but
  2. You should be surprised that you do observe that you are alive.

Indeed, it really is very improbable that you should have survived, so the surprise expressed in (2) is reasonable. What would be unreasonable would be responding to “How did you survive?” with “If I didn’t, I would not be here to answer you.” No, we would want to know what happened to leave him alive (his friends bribed the squad members, loaded all their guns with blanks, or he had a deflector shield, for example); we need a real explanation!

To use another analogy, where the real question is blown off as flippantly as Hawking blows off the fine-tuning:

Parent: “Why haven’t you cleaned your room as I asked you to?”
Child: “Well, if I had cleaned it, then you wouldn’t be asking me that.”

So returning to the fine-tuning, by analogy with point (2) above, we really should be surprised to find that the constants of the universe are so fine-tuned for life, because this combination is so improbable. So we need a proper explanation.

Objection 2: All states of affairs are highly improbable, therefore every individual state of affairs is a ‘miracle’.

However, although all combinations on a combination lock are equally improbable to obtain randomly, a bank manager does not think that anyone could open the lock by chance. No-one would explain a Shakespearian sonnet by a chimp typing randomly, although any randomly typed letter sequence is equally improbable (‘I love you dearly’ surely requires more explanation than ‘asnhouyganpi;kvk klkjfl’). See also Cheating with chance.

Related to this is a claim by an atheist called Richard Carrier, who has no scientific qualifications, regarding Craig’s arguments about fine-tuning, claiming basically that we can’t know how many possible combinations of constants would be able to produce a universe with life, so we can’t perform probability calculations:

We actually do not know that there is only a narrow life-permitting range of possible configurations of the universe. As has been pointed out to Craig by several theoretical physicists (from Krauss to Stenger), he can only get his “narrow range&dquo; by varying one single constant and holding all the others fixed, which is simply not how a universe would be randomly selected. When you allow all the constants to vary freely, the number of configurations that are life permitting actually ends up respectably high (between 1 in 8 and 1 in 4: see Victor Stenger’s The Fallacy of Fine-Tuning).
However, Australian non-creationist astrophysicist Dr Luke Barnes, a specialist in fine-tuning arguments,3 refuted this as follows:
Also, by saying “from” and “to”, Carrier is trying to give the impression that a great multitude stands with his claim. I’m not even sure if Krauss is with him. I’ve read loads on this subject and only Stenger defends Carrier’s point, and in a popular (ish) level book. On the other hand, Craig can cite Barrow, Carr, Carter, Davies, Deutsch, Ellis, Greene, Guth, Harrison, Hawking, Linde, Page, Penrose, Polkinghorne, Rees, Sandage, Smolin, Susskind, Tegmark, Tipler, Vilenkin, Weinberg, Wheeler, and Wilczek. (See here). With regards to the claim that “the fundamental constants and quantities of nature must fall into an incomprehensibly narrow life-permitting range”, the weight of the peer-reviewed scientific literature is overwhelmingly with Craig. (If you disagree, start citing papers).
“He can only get his ‘narrow range’ by varying one single constant”. Wrong. The very thing that got this field started was physicists noting coincidences between a number of constants and the requirements of life. Only a handful of the 200+ scientific papers in this field vary only one variable. Read this.
“1 in 8 and 1 in 4: see Victor Stenger”. If Carrier is referring to Stenger’s program MonkeyGod, then he’s kidding himself. That ‘model’ has 8 high school-level equations, 6 of which are wrong. It fails to understand the difference between an experimental range and a possible range, which is fatal to any discussion of fine-tuning. Assumptions are cherry-picked. Crucial constraints and constants are missing. Carrier has previously called MonkeyGod “a serious research product, defended at length in a technical article”. It was published in a philosophical journal of a humanist society, and a popular level book, and would be laughed out of any scientific journal. MonkeyGod is a bad joke.4

Objection 3: There are infinitely many universes.

But there is not the slightest evidence for them. In fact, no evidence is even possible, so proposal is unscientific. Better to believe in a supernatural designer, which has good analogical support. See also Stephen Hawking and multiverses.

Carrier’s argument is basically saying: you can’t prove that your car was designed, because we don’t know how many possible arrangements of matter could produce a powered land vehicle. However, we do know that there are almost infinitely more ways that matter could be arranged that would could not be a powered land vehicle.


  1. Barrow, John and Tipler, Frank, The Anthropic Cosmological Principle, Clarendon Press, 1986. Return to text.
  2. William Lane Craig, Barrow and Tipler on the Anthropic Principle vs. Divine Design, 2005; Critical review of The Anthropic Cosmological Principle, International Philosophical Ouarterly 27:437–47, 1987. Return to text.
  3. Barnes, L., The Fine-Tuning of the Universe for Intelligent Life,, 2 June 2012. Return to text.
  4. Barnes, L., Christmas Tripe—A Fine-Tuned Critique of Richard Carrier (Part 3), Letters to Nature blogspot, 23 December 2013; bold/italics in original. Return to text.

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