In the field of physics there are a set of mathematical constants, sometimes called the Cosmological Constants, used to describe certain observable phenomena. These constants include, for example, the speed of light, the force of gravity, and the rate of inflation of the universe.
Life, at least of the carbon-based types we find on Earth, seem to only be able to exist if each of these constants fall within a certain, quite limited range. If they were different by very much at all, then either stars could not have formed, or the universe would have collapsed in on itself almost immediately after expansion began, or any other variety of situations would occur that would not be compatible with enabling our form of life to exist.
And as you probably figured was the case, each of these parameters do in fact exist within the ranges necessary for our carbon-based forms of life to exist. Thus Theists have devised the Fine Tuning Argument which argues that the existence of a designer god is the best explanation for why these parameters exist within that limited range that enables our form of life to exist.
For example, the Theist website Biologos summarizes it like this:
Fine-tuning refers to the surprising precision of nature’s physical constants, and the beginning state of the Universe. To explain the present state of the universe, even the best scientific theories require that the physical constants of nature and the beginning state of the Universe have extremely precise values.
To help organize my response to the Fine Tuning Argument, I will lay out the logic of it more precisely. The argument has various formulations depending on who is making it, but the rationale always conforms to that shown below:
P1) Human life can only exist if the cosmological constants must have values that fall within a quite precise range.
P2) The cosmological constants fall within the precise ranges that enable the existence of human life, and human life exists.
P3) The only explanations are that the CC have those values by A) chance, or by B) design.
P4) It is very unlikely that the CC would fall within these precise ranges by chance, without being intentionally set.
P5) It would be guaranteed that the CC would fall within these precise ranges if they were set by design by an intelligent being.
P6) Therefore option B, that a being created our universe, is more probable.
In short, the Fine Tuning Argument is based on reasoning that if something which occurred appears to have been very unlikely, then in actuality it probably occurred due to something that was not unlikely. In other words, any apparently unlikely event was probably not an unlikely event.
Note on terms and abbreviations: The problem with using the term “fine tuning” as a label for the fact that the CC fall within certain ranges is that the words “fine tuning” are not neutral; they carry the connotation that the constants were set by intentional design.
Ideally, to be logical, we should not label facts using phrases that carry connotations that are not necessary parts of the fact itself. The fact is just that the universe has these particular parameters. To add conclusions about that fact into the label for the fact itself can make discussing the issue more difficult and confusing, and can produce bias.
I would rather use a different term altogether. But in this article, in order to avoid further confusion, I will use the terminology and definition employed by the Theistic apologists whose argument I am addressing. This means that I will use the term Fine Tuning to refer to the general fact that the cosmological constants (or rather, the characteristics of nature that they describe) exist within the limited range able to support our form of life. This usage will not imply either design or no design as the reason for it
Fine Tuning by Design (FTD) will refer to the parameters of the universe being set as they are by a designer being.
Furthermore, I will use the abbreviation ‘CC’ to refer to the cosmological constants as a group, and ‘FTA’ to refer to the Fine Tuning Argument itself.
1) Possible designers other than “God”
This section does not attempt to refute the FTA. Instead, in this section I raise an important point to keep in mind about the FTA which is this: Even if the FTA were logically sound, it would only support the idea of some designer or designers in general. The idea of a being like the modern Hindu personal god or Abrahamic god would not exclusively follow from the evidence of Fine Tuning.
1A) Only requires a few characteristics
A being that fits the common Theistic concept of “God” is not the only option for possible designers. This concept labeled God is considered to be conscious, omnipotent, omniscient, entirely good, chooses to create life, and exists by its nature (chance?) rather than by design.
That is quite an extreme list of traits. But there are only a few requirements to qualify as a match for the FTA’s conclusion:
– The designer(s) must exist in conditions that are not Fine Tuned by Theists’ standards, because otherwise the FTA would apply to the designer as well
– The designer(s) can have chosen to create life for any reason and with any intentions. They do not need to be all-good. For example, they may be running experiments, or they may wish to create life so that they can simply enjoy watching events unfold, like a form of entertainment.
– The designer(s) must possess only the minimum necessary amount of power and knowledge to create the universe we find ourselves in (they do not need to be omnipotent or omniscient).
– The designer or designers’ primary purpose in creating a universe that is capable of supporting life does not need to be any particular species, nor any life forms. Life may have been one part of what they intended to do, but not necessarily the primary purpose.
– There can be any number of designers working together. There does not need to be only one.
Any conclusions from the FTA beyond these minimal requirements would be unfounded assumptions and is therefore arbitrary and unlikely to be correct, as per the principle of Occam’s Razor.
1B) Conditions within the universe do not appear fine-tuned for life
The FTA focuses on the ability of life to exist at all, but it does not address challenges to Theism based on the particular ways in which life exists in the universe.
If a designer or designers had power to create the universe however they liked, and making it suitable for life to thrive was their primary intention, then logically we would expect the universe they created to be very different from the one in which we actually exist.
The conditions of the universe in which humans and other creatures must exist are actually are not very well suited for us. These conditions do not appear at all like one would expect of a universe designed specifically for life to thrive and be fulfilled. But they do appear just as one would expect of a universe not designed primarily for life, or even with life in mind at all.
For example, the universe is overwhelmingly comprised of empty, lifeless space; and this would be true even if every planet in every solar system were as capable of supporting life as Earth. But of course the planets are not like that. Many are severely hot or severely cold, have no water, have toxic and intolerant atmospheres, and so on. And vast portions of even our own planet are very harsh – or even inhospitable – including deserts and cold wastelands. Natural weather events cause horrendous disasters; the list goes on and on – and is even longer if you include the severe problems that a designer could have done differently in planning the evolution of organisms and how their bodies function.
Richard Carrier expressed similar views on the Fine Tuning Argument as being a clear indicator of there not being a designer:
“If there is no god, we will only ever find ourselves in a universe finely tuned (in that case, by random chance), because without a god, there is no other kind of universe that can produce us. Likewise, a universe that produced us by chance would have to be enormously vast in size and enormously old, so as to have all the room to mix countless chemicals countless times in countless places so as to have any chance of accidentally kicking up something as complex as life. And that’s exactly the universe we see: one enormously vast in size and age. A godless universe would also only produce life rarely and sparingly, and that’s also what we see: by far most of the universe is lethal to life (being a deadly radiation filled vacuum) and by far most of the matter in the universe is lethal to life (constituting stars and black holes on which no life can ever live). Again, all exactly what we’d expect of a godless universe. Not what we’d expect of a god-made one.”
It certainly seems like an irrational supposition that the design of the universe is centered around the purpose of enabling a particular aspect of it to exist, that takes billions of years to begin, arrives by no apparent guide, and that is scarce and barely able to survive when and where it barely appears.
The analogy has been made to finding a single iron atom in a rock and declaring, “This is the ideal source of iron! We could have had plain bars of it lying abundantly in the earth ready to be used and shaped by us, but no – this rock is ideal. And therefore I say that it must have been explicitly designed to supply us with usable iron by a wise and capable mind!”
If a designer or designers had chosen, they could have made a universe that were indeed designed for life. The entire universe could be made of earth below and sky above, just as many ancient cultures indeed imagined that it was. There would be no useless, empty abyss of air-less space. Vegetation useful for our form of life would be abundant everywhere and provide more than enough nutrients to need only a little each day, while calm rivers would flow through like the Paradise imagined in the Quran. The land would always be like summer, with no difficulty of a harsh winter where everything is covered and sleeps like it is dead – or indeed kills them. The temperature could always be between 70 and 80 degrees Fahrenheit, except for a few pockets of snowy mountains for recreation and for some varieties of creatures that the designer might want to see arise. The weather would be generally fair and not produce violent storms; the world’s primary source of light would not give us cancer or burn our skin; asteroids would not randomly strike the world killing millions of creatures; and so on.
Thus even if you think the FTA indicates a designer or designers, you would be faced with the conclusion that life was not its primary focus, or it lacked the ability to make it any more suitable for life.
2) Problems with Probability
The FTA is based on the assumption that the Fine Tuning of our universe is highly improbable simply due to the understanding that the values of the CC must exist within such a limited ranged for them to support life.
However, there are problems with that reasoning. Because of the nature of our situation and perspective, we lack information regarding how the values of the cosmological constants are assigned, and therefore we lack the contextual information necessary to determine the probability that our life-permitting universe would have come into existence.
The following subsections describe some of the reasons we cannot make a determination about probability.
2A) The Anthropic Principle.
The Anthropic Principle is a philosophical point which states that if and wherever life comes into existence, it will always exist in conditions that are compatible with life. It is impossible for any life form to ever observe that the conditions it exists in do not support life, because if those conditions did not support life then no life form would be able to exist there and observe them.
It is a quite simple realization and the fact seems quite obvious, but its implications are often misunderstood by Theists.
This principle presents a problem for the FTA because it means that if we indeed ever came to exist at all then the only possible universe we could ever find ourselves in is one that supports life, regardless of what the chances are for a universe that supports life to come into existence.
So the fact that the CC line up with values that enable our form of life to exist is meaningless in regard to probability because finding ourselves in such a universe would never be a coincidence. If life occurs at all, then it is guaranteed to find itself in a life-permitting universe, so without more information pertinent to this matter besides the CC themselves, we have no basis on which to judge whether this occurred by extremely low probability, extremely high probability, or anywhere in between.
2B) The possibility of equally unlikely outcomes.
The FTA is based on assuming that if there was no designer, the probability of us appearing is very low in comparison to the alternatives. But we lack information to judge what those chances would actually be if there was no designer, so we cannot logically conclude that our universe was uniquely unlikely and would therefore require an explanation that we rightfully would not demand for the other hypothetically potential outcomes.
But the FTA requires the view that if the CC were assigned their values on a random basis then our universe was less likely to occur than the alternatives. Without a basis for that view, the FTA lacks its central premise and thus cannot justify its conclusion.
By comparison, consider a deck of 52 playing cards. A person can shuffle the deck and then lay out the cards in a totally random sequence on a table. In this situation, every possible outcome – that is, every possible sequence of cards – is equally unlikely to have been laid out on the table. But simply because the cards were being laid out at all, the probability that one of those events would occur was 100%. So in that context we can understand that the fact one of those situations occurs is not actually unlikely or remarkable at all.
What this means for Fine Tuning is that the fact our universe supports life indicates nothing except that the universe began at all (which would make this merely an issue of First Cause, not probability).
2C) The possibility of life being highly probable.
Since we cannot determine the probability of a life-permitting universe coming into existence, we must even be open to the possibility that it was actually highly likely that a life-permitting universe would come into existence.
This can be due to restrictions in physics (such as if all of reality is deterministic) or so many universes naturally forming that the statistical likelihood of one or more of them supporting life is extremely high. I will discuss some of these in Section 3 below.
3) A designer is not the most probable explanation for the existence of a life-sustaining universe
As I explained in section 2, it is possible that all the potential outcomes of the creation of the universe were equally unlikely and therefore no particular outcome indicates that there must be an explanation for its occurrence beyond random chance.
That is enough to render the FTA’s conclusion about a designer incorrect. But what if it had indeed been very unlikely that a life-permitting universe would come into existence? In that case, would the FTA indeed indicate that a cosmic designer probably exists? I think the answer is “No”.
I say that because there are explanations for why unlikely life-permitting conditions would have come into existence that are more direct and make fewer assumptions than the hypothesis of a cosmic designer. I listed the requirements for an FTA-compatible cosmic designer in section 1A, and as such a designer compares with alternative hypotheses, those traits also qualify as necessary assumptions of the hypothesis which must be compared against the necessary assumptions of other hypotheses.
Below I have listed several hypotheses that I believe are more direct explanations than the designer hypothesis to explain the unlikely existence of our universe if indeed it is unlikely.
Just as there are multiple galaxies, there may be billions or infinite universes which form with different characteristics of physics -i.e. different values for the cosmological constants. This theory would mean that so many universes exist that there was a very high chance of one or more of them being able to support our form of life; then the Anthropic Principle mentioned earlier explains why it is no coincidence at all that we find ourselves in one of the particular universes that is capable of supporting life. Since we already know that one universe exists, the notion of there simply being multiple universes seems like a simpler explanation than the list of factors associated with a cosmic designer.
B) Rebounding Universe.
This theory states that perhaps our universe is the only one in existence, but that it collapses into a singularity then expands again in repeated cycles. In each of these expansion events – which you could call Big Bangs – the CC randomly take on different values (that is to say, the nature of the characteristics of the universe which the CC describe are what change). Just like the Multiverse theory, this theory would mean that there was a very high probability of a life-permitting universe forming without a designer.
C) Many-Worlds Interpretation of Quantum Mechanics.
This interpretation of the evidence in quantum mechanics holds that all potential outcomes of every quantum process are actually manifested in the formation of a parallel universe at every moment in time. This would mean that every possible potential set of values for the CC would inevitably occur in some universe and we are simply experiencing one of those universes.