Tag Archives: Life

The formation of the elements required for complex embodied life is fine-tuned

Apologetics and the progress of science
Apologetics and the progress of science

Some atheists who don’t understand the fine-tuning argument like to assert that the constants and quantities that are fine-tuned to allow for the existence of complex, embodied life can be changed arbitrarily, and life would still exist as it does now. They say that maybe we would have a ridges in our foreheads like Klingons, or maybe we would have longer ears like Vulcans or maybe green skin like Orions. The evidential support for this view seems to be grounded in Star Trek TV shows, not peer-reviewed evidence. Are atheists right to ground their rejection of a cosmic Designer in science fiction television shows? What does the peer-reviewed research say?

The fine-tuning argument

First, let’s review the structure of the fine-tuning argument.

The argument goes like this:

  1. The fine-tuning of the universe to support life is either due to law, chance or design
  2. It is not due to law or chance
  3. Therefore, the fine-tuning is due to design

Although each permutation of values for the constants and quantities is equally improbable, the vast majority of the permutations will not permit life.

Let’s review:

  • Life has certain minimal requirements; long-term stable source of energy, a large number of different chemical elements, an element that can serve as a hub for joining together other elements into compounds, a universal solvent, etc.
  • In order to meet these minimal requirements, the physical constants, (such as the gravitational constant), and the ratios between physical constants, need to be withing a narrow range of values in order to support the minimal requirements for life of any kind.
  • Slight changes to any of the physical constants, or to the ratios between the constants, will result in a universe inhospitable to life.
  • The range of possible values spans 70 orders of magnitude.
  • The constants are selected by whoever creates the universe. They are not determined by physical laws. And the extreme probabilities involved required put the fine-tuning beyond the reach of chance.
  • Although each individual selection of constants and ratios is as unlikely as any other selection, the vast majority of these possibilities do not support the minimal requirements of life of any kind. (In the same way as any hand of 5 cards that is dealt is as likely as any other, but you are overwhelmingly likely NOT to get a royal flush. In our case, a royal flush is a life-permitting universe).

Now let’s see a specific example: carbon and oxygen formation.

Carbon is that element that can serve as a hub for larger molecules, and oxygen is also a vital element, since it is a component of water, which is required for life (universal solvent). Both are required for complex life of any imaginable kind.

Now for the study.

Here is an article on Science Daily about the fine-tuning argument.

It says:

Life as we know it is based upon the elements of carbon and oxygen. Now a team of physicists, including one from North Carolina State University, is looking at the conditions necessary to the formation of those two elements in the universe. They’ve found that when it comes to supporting life, the universe leaves very little margin for error.

Both carbon and oxygen are produced when helium burns inside of giant red stars. Carbon-12, an essential element we’re all made of, can only form when three alpha particles, or helium-4 nuclei, combine in a very specific way. The key to formation is an excited state of carbon-12 known as the Hoyle state, and it has a very specific energy — measured at 379 keV (or 379,000 electron volts) above the energy of three alpha particles. Oxygen is produced by the combination of another alpha particle and carbon.

NC State physicist Dean Lee and German colleagues Evgeny Epelbaum, Hermann Krebs, Timo Laehde and Ulf-G. Meissner had previously confirmed the existence and structure of the Hoyle state with a numerical lattice that allowed the researchers to simulate how protons and neutrons interact. These protons and neutrons are made up of elementary particles called quarks. The light quark mass is one of the fundamental parameters of nature, and this mass affects particles’ energies.

In new lattice calculations done at the Juelich Supercomputer Centre the physicists found that just a slight variation in the light quark mass will change the energy of the Hoyle state, and this in turn would affect the production of carbon and oxygen in such a way that life as we know it wouldn’t exist.

[…]The researchers’ findings appear in Physical Review Letters.

There are many, many other examples of fine-tuning of the constants and quantities to permit complex, embodied life. And, as we’ll see below, this evidence is admitted by atheists.

Atheists agree: the fine-tuning is a fact

Let me give you a citation from the best one of all, Martin Rees. Martin Rees is an atheist and a qualified astronomer. He wrote a book called “Just Six Numbers: The Deep Forces That Shape The Universe”, (Basic Books: 2001). In it, he discusses 6 numbers that need to be fine-tuned in order to have a life-permitting universe.

In chapter 1, Rees writes:

Mathematical laws underpin the fabric of our universe — not just atoms, but galaxies, stars and people. The properties of atoms — their sizes and masses, how many different kinds there are, and the forces linking them together — determine the chemistry of our everyday world. The very existence of atoms depends on forces and particles deep inside them. The objects that astronomers study — planets, stars and galaxies — are controlled by the force of gravity. And everything takes place in the arena of an expanding universe, whose properties were imprinted into it at the time of the initial Big Bang.

[…]This book describes six numbers that now seem especially significant.

[…]Perhaps there are some connections between these numbers. At the moment, however, we cannot predict any one of them from the values of the others.

[…]These six numbers constitute a ‘recipe’ for a universe. Moreover, the outcome is sensitive to their values: if any one of them were to be ‘untuned’, there would be no stars and no life. Is this tuning just a brute fact, a coincidence? Or is it the providence of a benign Creator?

There are some atheists who deny the fine-tuning, but these atheists are in firm opposition to the progress of science. The more science has progressed, the more constants, ratios and quantities we have discovered that need to be fine-tuned. Science is going in a theistic direction. Next, let’s see how atheists try to account for the fine-tuning.

Atheistic responses to the fine-tuning evidence

There are two common responses among atheists to this argument.

The first is to speculate that there are actually an infinite number of other universes that are not fine-tuned, (i.e. – the gambler’s fallacy). All these other universes don’t support life. We just happen to be in the one universe is fine-tuned for life. The problem is that there is no way of directly observing these other universes and no independent evidence that they exist.

Here is an excerpt from an article in Discover magazine, (which is hostile to theism and Christianity).

Short of invoking a benevolent creator, many physicists see only one possible explanation: Our universe may be but one of perhaps infinitely many universes in an inconceivably vast multiverse. Most of those universes are barren, but some, like ours, have conditions suitable for life.

The idea is controversial. Critics say it doesn’t even qualify as a scientific theory because the existence of other universes cannot be proved or disproved. Advocates argue that, like it or not, the multiverse may well be the only viable non­religious explanation for what is often called the “fine-tuning problem”—the baffling observation that the laws of the universe seem custom-tailored to favor the emergence of life.

The second response by atheists is that the human observers that exist today, 14 billion years after the universe was created out of nothing, actually caused the fine-tuning by going back in time and causing the universe to be fine-tuned. This solution would mean that although humans did not exist at the time the of the big bang, they are going to be able to reach back in time at some point in the future and manually fine-tune the universe.

Here is an excerpt from and article in the New Scientist, (which is hostile to theism and Christianity).

…maybe we should approach cosmic fine-tuning not as a problem but as a clue. Perhaps it is evidence that we somehow endow the universe with certain features by the mere act of observation… observers are creating the universe and its entire history right now. If we in some sense create the universe, it is not surprising that the universe is well suited to us.

So, there are two choices for atheists. Either an infinite number of unobservable universes that are not fine-tuned, or humans go back in time at some future point and fine-tune the beginning of the universe, billions of years in the past. I think I will prefer the design explanation to those alternatives.

Positive arguments for Christian theism

Lawrence Krauss debates “A Universe From Nothing” with an astrophysicist

Two horses fight it out, may the best horse win!
Two horses fight it out, may the best horse win!

Dina sent me news of a cracking good episode of Unbelievable, which features Lawrence Krauss, who debated William Lane Craig. Krauss’ book was also reviewed in the New York Times.

The MP3 file is here.

Details:

Lawrence Krauss is a Cosmologist at Arizona State University who describes himself as an “anti-theist”. His latest book “A Universe From Nothing” has received both acclaim and criticism for its attempt to answer the question “Why is there something rather than nothing?” Debating the issue with Krauss is Rodney Holder, Course director at the Faraday Institute, Cambridge. An astrophysicist and priest by background. In a lively exchange they debate whether Krauss’ “nothing” is “nothing”, fine tuning and multiverses, scientific knowledge, miracles and the usefulness of theology and philosophy.

This debate is quite entertaining, and do not be intimidated if your don’t understand science. You can understand pretty easily who is arguing based on facts and who is speculating about unobservable, untestable entities. At one point, Krauss actually denies that there is any fine-tuning in the universe, so please see this link to refute that claim as well as this podcast which explains some examples of fine-tuning. Krauss gets a bit angry at the beginning, but calms down.

Quotation marks are for direct quotes, italics is for made-up snark. See below the summary for more posts that are related to this one.

Summary of the discussion: (picked up at 9:30 when they start talking about the book)

Brierley:

  • explain your theory of how the universe can come into being from nothing

Krauss:

  • the nothing that preceded the universe is “no space, no time, no universe”
  • theists say that God is responsible for creating the universe out of this nothing
  • but the laws of nature can create the universe uncaused out of nothing

Holder:

  • Krauss sometimes writes that the nothing is really a quantum vacuum, but that is not nothing
  • He even acknowledges in his book that a quantum vacuum is not nothing
  • He thinks that the nothing has properties, even though it has no being
  • It has the property of being unstable
  • It has the property of being acted on by quantum fields
  • It has the property of being acted on by gravity

Krauss:

  • But nothing can have the potential to do things inside it
  • For example suppose you have an electron, which is not nothing
  • If it jumps from one level to another, it emits light
  • There was no potential for the light in the electron, but it was there as part of atomic structure

Holder:

  • But in cases like that, there is something physical that has the potential
Krauss:
  • Well, how did God makes the universe then if it had no potential?

Holder:

  • God existed, and the potential for creating the universe in himself

Brierley:

Krauss:
  • It was written by a philosopher, so I dismissed it

Brierley:

Krauss:
  • These book reviewers have not even read my book!

Krauss:

  • Science will be able to figure out how to make something from nothing in the future
  • We are even now speculating about interesting questions, like is there a multiverse?

Brierley:

  • Consider the critical review of your book in the New York Times
  • The author of the review claims that you equivocate on the term “nothing”
  • In order to get things to pop into being, you have to make “nothing” mean “something”
  • Reviewer: none of Krauss’ theories explain how something can come from actual nothingness

Krauss:

  • In physics, something and nothing are not that different
  • The reviewer doesn’t understand the physics
  • He doesn’t understand quantum field theory
  • You could call a quantum vacuum “nothing”, (this is the vacuum fluctuation model, refuted by William Lane Craig in a peer-reviewed publication in an astrophysics journal – get the full text of the article here)
  • Maybe there is an eternally existing multiverse that we can’t observe or test scientifically
  • Maybe it has laws that we don’t know about which allow our universe to pop into being
  • Maybe this popping into being is uncaused
  • (alarmed) Who made God? Who made God?

Holder:

  • God is eternal and necessary

Krauss:

  • (interrupting, angry) What does it mean for something to be necessary?

Holder:

  • Basically, you have to decide whether there is more evidence that the necessary being God or a multiverse

Brierley:

  • So Dr. Krauss are you willing to say that the universe is a brute fact, in some sense, and requires no explanation

Krauss:

  • (angry) Religious people are stupid because they just assume brute facts, not like me and my unobservable, untestable multiverse
  • (angry) Religious people are against the progress of science, they don’t want to figure out how things work

Brierley:

  • But isn’t it possible that naturalists can be opposed to the progress of science?
  • What about the way the Fred Hoyle opposed the Big Bang because he wanted an eternal universe

Krauss:

  • (angry) But naturalists like me let the facts determine our beliefs, like the facts about the eternal unobservable, untestable multiverse
  • (angry, shouting) Philosophers are stupid, they know nothing!

=== Break ===

Brierley:

  • Do you see any evidence of purpose in the universe?

Krauss:

  • Well maybe I would believe if the stars lined up to spell out a message from God

Brierley:

  • Actually no, that wouldn’t be evidence for God on your multiverse view
  • if there an infinite number of universes existing for an infinite amount of time, then anything can happen no matter how unlikely it is
  • therefore, no evidence could convince you that God exists, since the unobservable, untestable, eternal multiverse can make anything it wants

Krauss:

  • That’s a true statement, and very convenient for atheists who don’t want to be accountable to God, don’t you think?
Brierley:
  • Back to the multiverse, how does it solve the fine-tuning?

Krauss:

  • “We have no idea if the universe is fine-tuned for life”, even though the atheist Martin Rees who endorsed Krauss’ book wrote his own book about the fine-tuning of the universe called “Just Six Numbers”
  • Inflationary theory does suggest a way to create multiple universes, (this is the chaotic inflationary model, refuted by William Lane Craig in a peer-reviewed publication in an astrophysics journal – get the full text of the article here)

Brierley:

  • But this theory is still very much a hypothesis, isn’t it? We can’t observe or test this hypothesis can we?

Krauss:

  • “No, and that is really important to state”
  • “I’m an empiricist, so if you can’t falsify it and if you can’t test it then it’s not science”
  • In my book, I speculate about a way that we could test the multiverse theory

Holder:

  • Yes, in principle, the multiverse would be scientific if you could test it through other theories like inflationary theory
  • There are a lot of speculations about multiverse theory, but no evidence from predictions that were validated in the lab

Krauss:

  • “I agree completely with everything you just said”

Brierley:

  • Roger Penrose agrees with Holder that the multiverse theory is too speculative
  • (To Holder) Isn’t the multiverse theory better than positing a completely different kind of being, which is God?

Holder:

  • The multiverse theory is extremely speculative
  • Even if the multiverse were true, you would still need to explain the multiverse

Krauss:

  • People don’t oppose my book because it’s full of self-contradictory speculations
  • People oppose my book because they are stupid and ignorant

Holder:

  • There are things that exist that science cannot measure, like objective morality
  • It’s possible to give explanations for moral behavior by appealing to evolution
  • But that does not ground self-sacrificial morality, such as what occurs in the Christian life

Brierley:

  • Dawkins says there is no purpose or morality in in the universe, do you agree?

Krauss:

  • “There is certainly no evidence of any of that”

Brierley:

  • In the book, you talk about how we live in a special time in the universe’s history to be able to do science, (i.e. – The Privileged Planet hypothesis)
  • You also write about how all the discoveries were are making will not be communicated to anyone in other places in the universe
  • So what is the meaning of doing science on your view? And why are you sad at the knowledge that will not be available to people in the future?
  • Are you longing for some kind of purpose?

Krauss:

  • No, I just get enjoyment from studying the universe with science to gain understanding

Holder:

  • What do you make of Einstein’s statement about the unexpected comprehensibility of the universe
  • Theists would say that this is because God wanted us to study and understand and gain knowledge

Krauss:

  • “It is remarkable that the universe is comprehensible”

Brierley:

  • Why is the universe comprehensible?

Krauss:

  • Well, maybe the universe just has to be that way

Brierley:

  • What do you make of the heat death of the universe, when all life in the universe will die out?

Krauss:

  • That’s the way the universe is
=== BREAK ===

Krauss:

  • I wouldn’t want to live in a universe where there was a God
  • God is a cosmic Saddam Hussein
  • “Religious people turn their minds off” and believe in God for consolation

Holder:

  • First, Jesus is the revelation of God and he is no Saddam Hussein
  • Second, the Christian life is anything but easy, we are facing some persecution already in the UK
  • Third, there is also the problem of being accountable to God when we die
  • It’s very much like science – Christianity is the way it is, not the way we want it to be

Krauss:

  • “If you don’t believe in him, you don’t get any of the benefits, so you have to believe”
  • “And then if you’ve done something wrong, you’re going to be judged for it”
  • “So I don’t want to be judged by God, I want to be… that’s the bottom line”

Holder:

  • Well, Jesus has died to pay the price for those things we’ve done wrong
  • Although we will have to face the charges for what we’ve done, believers will ultimately be forgiven

UPDATE: Peter Sean Bradley note that Krauss is now walking back his rhetoric in response to criticisms from people like atheist John Horgan.

Related posts

Can naturalism account for the origin of the 20 amino acids in living systems?

Do the Miller-Urey experiments simulate the early Earth?
Do the Miller-Urey experiments simulate the early Earth?

The origin of life

There are two problems related to the origin of the first living cell, on naturalism:

  1. The problem of getting the building blocks needed to create life – i.e. the amino acids
  2. The problem of creating the functional sequences of amino acids and proteins that can support the minimal operations of a simple living cell

Normally, I concede the first problem and grant the naturalist all the building blocks he needs. This is because step 2 is impossible. There is no way, on naturalism, to form the sequences of amino acids that will fold up into proteins, and then to form the sequences of proteins that can be used to form everything else in the cell, including the DNA itself. But that’s a topic for a separate post.

Today, let’s take a look at the problems with step 1.

The problem of getting the building blocks of life

Now you may have heard that some scientists managed to spark some gasses to generate most of the 20 amino acids found in living systems. These experiments are called the “Miller-Urey” experiments.

The IDEA center has a nice summary of origin-of-life research that explains a few of the main problems with step 1.

Miler and Urey used the wrong gasses:

Miller’s experiment requires a reducing methane and ammonia atmosphere,11, 12 however geochemical evidence says the atmosphere was hydrogen, water, and carbon dioxide (non-reducing).15, 16 The only amino acid produced in a such an atmosphere is glycine (and only when the hydrogen content is unreasonably high), and could not form the necessary building blocks of life.11

Miller and Urey didn’t account for UV of molecular instability:

Not only would UV radiation destroy any molecules that were made, but their own short lifespans would also greatly limit their numbers. For example, at 100ºC (boiling point of water), the half lives of the nucleic acids Adenine and Guanine are 1 year, uracil is 12 years, and cytozine is 19 days20 (nucleic acids and other important proteins such as chlorophyll and hemoglobin have never been synthesized in origin-of-life type experiments19).

Miller and Urey didn’t account for molecular oxygen:

We all have know ozone in the upper atmosphere protects life from harmful UV radiation. However, ozone is composed of oxygen which is the very gas that Stanley Miller-type experiments avoided, for it prevents the synthesis of organic molecules like the ones obtained from the experiments! Pre-biotic synthesis is in a “damned if you do, damned if you don’t” scenario. The chemistry does not work if there is oxygen because the atmosphere would be non-reducing, but if there is no UV-light-blocking oxygen (i.e. ozone – O3) in the atmosphere, the amino acids would be quickly destroyed by extremely high amounts of UV light (which would have been 100 times stronger than today on the early earth).20, 21, 22 This radiation could destroy methane within a few tens of years,23 and atmospheric ammonia within 30,000 years.15

And there were three other problems too:

At best the processes would likely create a dilute “thin soup,”24 destroyed by meteorite impacts every 10 million years.20, 25 This severely limits the time available to create pre-biotic chemicals and allow for the OOL.

Chemically speaking, life uses only “left-handed” (“L”) amino acids and “right-handed” (“R)” genetic molecules. This is called “chirality,” and any account of the origin of life must somehow explain the origin of chirality. Nearly all chemical reactions produce “racemic” mixtures–mixtures with products that are 50% L and 50% R.

Two more problems are not mentioned in the article. A non-peptide bond anywhere in the chain will ruin the chain. You need around 200 amino acids to make a protein. If any of the bonds is not a peptide bond, the chain will not work in a living system. Additionally, the article does not mention the need for the experimenter to intervene in order to prevent interfering cross-reactions that would prevent the amino acids from forming.

Usually when you hear the origin of life debated, they sort of skirt about the problem of where the amino acids come from, but there is no reason not to make that an issue. The naturalist has to explain how the first living cell could come about naturalistically.

Positive arguments for Christian theism

 

What did early church fathers think about abortion and infanticide?

Unborn baby scheming about early church traditions
Unborn baby scheming about early church traditions

This is from Birds of the Air.

Summary:

Recently I came across a reading of the Didache. “The what?” you may ask. The Didache is a book written somewhere in the first or second century. For a long time it was up for consideration as Scripture. It was believed to be the Teaching of the Twelve Apostles. Eventually it was agreed that the book was an excellent book, but not inspired Scripture. So I was pleased to be able to download this admirable book containing good teachings from the early Church fathers.

The book seemed to be largely a lot of quotes from Scripture. You’ll learn the basic rules of Christianity — “First, you shall love God who made you; second, love your neighbor as yourself.” You’ll learn that “grave sins” are forbidden, like adultery, murder, fornication, and so on. (They specifically include pederasty in the list.) There are instructions regarding teachers, prophets, Christian assembly, and so on. Lots of the normal, good stuff. But, since this was written sometime prior to 200 AD, I was somewhat surprised at this instruction: “You shall not murder a child by abortion” (Didache, Ch 2).

I got curious about what babies look like when they are just a few weeks old, so I went looking for pictures of them.

This post from Life News has ten excellent pictures of life inside the womb.

Here’s my favorite from 10 weeks:

Unborn Baby - 10 weeks old
Unborn Baby – 10 weeks old

This is a first trimester baby!

I decided to go hunting to see what is developed at this time, and found this list:

  • From this week until birth, the developing organism is called a fetus.
  • The fetus is now the size of a small strawberry.
  • The feet are 2mm long (one tenth of an inch).
  • The neck is beginning to take shape.
  • The body muscles are almost developed. Baby has begun movement.
  • While still too small for you to feel, your little one is wriggling and shifting.
  • The jaws are in place. The mouth cavity and the nose are joined.
  • The ears and nose can now be seen clearly.
  • Fingerprints are already evident in the skin.
  • Nipples and hair follicles begin to form.

The unborn baby is now called a fetus. Though the fetus is constantly moving, you will not be able to actually feel fetal movement for several more weeks. All of the organs, muscles, and nerves are in place and beginning to function. As the hands and feet develop fingers and toes, they have lost their paddle like look. The touch pads on the fingers form and already have fingerprints.

During this week of pregnancy the crown to rump length of the fetus is 0.9 inch to 1.2 inches (22 to 30mm), weight 0.07 ounce (2gm). They are now on the way to forming their testicles or ovaries, getting ready for the next generation. Until the ninth week of fetus development, the fetal reproductive apparatus is the same one for the both sexes. The head is still large and curves into chest.

Each week your uterus grows larger with the baby growing inside it. You may begin to see your waistline growing thicker by this time. A pelvic exam will detect that your uterus has grown from it’s normal, size of your fist, to a little bigger than a grapefruit.

Fascinating!

Philosopher Doug Groothuis explains the logic of the pro-life position

I'm Scheming Unborn Baby, and I approve this study
I’m Scheming Unborn Baby, and I approve this message

At Christian Post, an article by Douglas Groothuis. (H/T Mary)

Here’s the most useful bit:

When we separate personhood from humanity, we make personhood an achievement based on the possession of certain qualities. But what are these person-constituting qualities? Some say a basic level of consciousness; others assert viability outside the womb; still others say a sense of self-interest (which probably does not obtain until after birth). All of these criteria would take away humanity from those in comas or other physically compromised situations.4 Humans can lose levels of consciousness through injuries, and even infants are not viable without intense and sustained human support. Moreover, who are we to say just what qualities make for membership in the moral community of persons?5 The stakes are very high in this question. If we are wrong in our identification of what qualities are sufficient for personhood and we allow a person to be killed, we have allowed the wrongful killing of nothing less than a person. Therefore, I argue that personhood should be viewed as a substance or essence that is given at conception. The fetus is not a lifeless mechanism that only becomes what it is after several parts are put together—as is the case with a watch or an automobile. Rather, the fetus is a living human organism, whose future unfolds from within itself according to internal principles. For example, the fertilized ovum contains a complete genetic code that is distinct from that of the mother or father. But this is not a mere inert blueprint (which is separable from the building it describes); this is a living blueprint that becomes what its human nature demands.

Yet even if one is not sure when personhood becomes a reality, one should err on the side of being conservative simply because so much is at stake. That is, if one aborts a fetus who is already a person, one commits a deep moral wrong by wrongfully killing an innocent human life. Just as we do not shoot target practice when we are told there may be children playing behind the targets, we should not abortion fetuses if they may be persons with the right not to be killed. As I have argued, it cannot be disputed that abortion kills a living, human being.

Many argue that outside considerations experienced by the mother should overrule the moral value of the human embryo. If a woman does not want a pregnancy, she may abort. But these quality of life considerations always involve issues of lesser moral weight than that of the conservation and protection of a unique human life (which considers the sanctity or innate and intrinsic value of a human life).6 An unwanted pregnancy is difficult, but the answer is not to kill a human being in order to end that pregnancy.

I think that the real question in the abortion debate right now is whether a living organism with a human nature and a human genetic code that is distinct from its mother and father deserves the right to life, or whether it needs to develop some other capability in order to be worthy of protection from violence.

Consider something from philosopher Francis J. Beckwith.

Excerpt:

Some argue that personhood does not arrive until brain waves are detected (40 to 43 days).11Others, such as Mary Anne Warren,12 define a person as a being who can engage in cognitive acts such as sophisticated communication, consciousness, solving complex problems, self-motivated activity and having a self-concept. This would put the arrival of personhood at some time after birth. Still others, such as L. W. Sumner, 13 hold a more moderate position and argue that human personhood does not arrive until the fetus is sentient, the ability to feel and sense as a conscious being. This, according to Sumner, occurs possibly as early as the middle weeks of the second trimester of pregnancy and definitely by the end of that trimester.

Although these criteria differ from each other in important ways, they all have one thing in common: each maintains that if and only if an entity functions in a certain way are we warranted in calling that entity a person. Defenders of these criteria argue that once a human being, whether born or unborn, acquires a certain function or functions–whether it is brain waves, rationality, sentience, etc.– it is then and only then that a person actually exists. Those who defend these personhood criteria typically make a distinction between “being a human” and “being a person.” They argue that although fetuses are members of the species homo sapiens, and in that sense are human, they are not truly persons until they fulfill a particular set of personhood criteria.

Although functional definitions of personhood may tell us some conditions that are sufficient to say that a being is a person, they are not adequate in revealing to us all the conditions that are sufficient for a particular being to be called a person. For example, when a human being is asleep, unconscious, and temporarily comatose, she is not functioning as a person as defined by some personhood criteria. Nevertheless, most people would reject the notion that a human being is not a person while in any of these states. In other words, while personhood criteria, such as the ones presented by Warren can tell us that a being is a person, these criteria are not adequate to declare a being a non-person: The exercise of rational thought tells us that a being is a person; when that person is sleeping, and thus is not exercising rational thought, that lack of exercise of the thought function does not make her a non-person at that time. Consequently, it seems more consistent with our moral intuitions to say that personhood is not something that arises when certain functions are in place, but rather is something that grounds these functions, whether or not they are ever actualized in the life of a human being. Thus, defining personhood strictly in terms of function is inadequate.

If you are pro-life because of your feelings, or because someone told you to be, you ought to know that being pro-life is quite rational and supported by medical evidence. People who are pro-abortion are pro-abortion because they want recreational sex without the complications of having to care for the consequences (babies!) of their own actions. Even if they do not engage in the sex and the abortions themselves, they advocate for abortion rights, and they are guilty of encouraging a culture where 57 million unborn children have died since 1973. We’re long past Stalin numbers with this thing now.

We ought to care about not hurting other people. If grown-up’ selfish pursuit of happy feelings conflicts with another person’s right to life, then maybe we need to take a step back from being happy and start trying to be good instead.