Cogito, Ergo Sum

When Does the Law Say Life Begins and Ends?

Martin A. Ginsburg

June 25, 2025

We likely all know the phrase “I think, therefore I am.” It’s a philosopher’s line, but our laws quietly live by something very close to it.

In the United States, we already use the brain—the organ that makes thinking possible—to decide when a person’s life has ended. But when we argue about abortion, personhood, and embryos, we often act as if the brain doesn’t matter at all.

This piece is about one simple, public question:

If the law says you stop being a legal “person” when your brain stops working forever,then why should the law say you start being a legal “person” before a brain exists at all?

You don’t have to agree on abortion policy to see that the rules at each end of life should at least talk to each other. And in a country with many faiths and philosophies, we need a standard that we can explain in secular, shared language—not just in the language of any one theology.

1. How the law says you are dead

Most of us assume death is obvious: the heart stops, the chest doesn’t rise, the person is gone.

But modern medicine made things more complicated. Machines can keep a heart beating and lungs inflating even when the brain is destroyed. So in 1980, a model law called the Uniform Determination of Death Act (UDDA) gave states a clear legal definition of death:

An individual is dead if they have either(1) irreversible loss of heart and lung function, or(2) irreversible loss of all functions of the entire brain, including the brainstem,determined under accepted medical standards.

All 50 states have adopted some version of this standard.

What this means in plain language:

A person on a ventilator whose brain has permanently stopped functioning can be declared legally dead, even if:

• Their heart is still beating with support.

• Their cells are alive.

• Their body is warm and looks “at rest,” not like a corpse.

We do this because we have quietly accepted that:

A human body without a functioning brain is no longer a living person, even if the tissues are alive.

The law is concerned with the person—the being capable of thought, feeling, relating to others, and experiencing the world as a subject—not just with warm flesh.

So, at the end of life, our law is already close to:

“When there is no longer any function of the entire brain, including the brainstem, the person is gone.”

We don’t wait for every cell to die. We use a functional test tied to the brain.

If brain function is central to how the law recognizes the end of a legal person, the obvious question is what the law does—if anything comparable—at the beginning.

2. How the law treats life before birth

At the other end of life, before birth, the law is much more fractured.

2.1. From Roe to Dobbs: who decides?

For almost 50 years, Roe v. Wade and then Planned Parenthood v. Casey said there was a federal constitutional right to choose abortion before the fetus (the later developmental stage in pregnancy) was viable (able to survive outside the womb with medical help). In 2022, the Supreme Court’s decision in Dobbs v. Jackson Women’s Health Organization overruled Roe and Casey and said:

The Constitution does not itself grant a right to abortion.

The power to regulate abortion belongs to “the people and their elected representatives” in each state.

So today:

• Some states heavily restrict or almost completely ban abortion.

• Others continue to allow it under a wide range of circumstances.

• The starting point for legal personhood before birth is not uniform.

2.2. “Unborn victims” and fetal homicide laws

On top of abortion law, we have fetal homicide and “unborn victims” laws.

• At the federal level, statutes like 18 U.S.C. § 1841 (the “Unborn Victims of Violence Act”) and 10 U.S.C. § 919a (military code) allow separate criminal charges when violence against a pregnant woman injures or ends the pregnancy of a “child in utero.”

• Many states also let prosecutors charge a separate offense if someone attacks a pregnant woman and harms or ends the pregnancy.

These laws treat the fetus as a second victim in certain crimes, even where abortion is legal.

They don’t, by themselves, completely answer the question “Is a fetus a 14th Amendment ‘person’?” But they get very close to person-like treatment in specific contexts.

2.3. Personhood-from-conception laws and proposals

Some states and advocacy groups want to go further and declare that:

A fertilized egg (a one-cell zygote) is a “person” with the same right to life as a newborn.

These personhood laws and ballot initiatives aim to lock in conception as the start of full legal personhood:

• Sometimes in state constitutions.

• Sometimes in criminal codes.

• Sometimes in civil wrongful-death statutes.

If they succeed, ending a pregnancy at any stage can be treated as killing a full legal person, with all the criminal and civil consequences that implies.

But remember: at the end of life, we decided that brain function, not mere biological possibility, potentiality, or existence defines when the person is gone.

Now we’ve set ourselves up for a tension.

That tension becomes easiest to see when we compare two real-world cases side by side.

3. The mismatch: two different rules for “person”

Let’s put this concretely.

Imagine two hospital rooms:

In the first, a 25-year-old named Jordan has suffered a devastating brain injury. Ventilators and machines keep Jordan’s heart beating and lungs moving. Tests show:

• No brain activity.

• No brainstem reflexes.

• No chance of recovery.

Under the UDDA and state law, Jordan can be declared legally dead, even though:

• Jordan’s cells are alive.

• Machines are still running.

• The body is warm.

In the second room, someone is two weeks pregnant. The embryo (the early developing organism, before the fetal stage):

• Is extremely small.

• Has no brain yet.

• Has no capacity for consciousness or thought.

• Cannot survive outside the uterus.

Yet under a personhood-from-conception law, that embryo is treated as a full legal person—sometimes called an “unborn child”—with a right to life equal to any adult’s.

So, side by side:

• A person declared dead by neurologic criteria can have a beating heart and still not be a legal person anymore.

• An embryo with no developed brain structures can be treated as a full legal person in certain states’ eyes.

This is not about whether embryos deserve some moral consideration. It’s about consistency:

If we say that the loss of all brain function means there is no longer a person, what neutral, equality-based rationale permits the law to treat a being with no developed brain function as a “person” while treating a brain-dead adult as no longer a person?

At minimum, the law owes us an explanation that does not depend on any particular theological doctrine.

4. Why theology can be protected without ruling everyone’s lives

The Supreme Court has been very clear about one thing:

Courts are not allowed to decide whether someone’s religious beliefs are logical, consistent, or even comprehensible.

In discussing the First Amendment, the Court has said:

“Religious beliefs need not be acceptable, logical, consistent, or comprehensible to others in order to merit First Amendment protection.”

That line is important for two reasons:

1. It protects people whose beliefs sound strange or illogical to others. Your beliefs about G_D, the soul, or when life begins don’t have to make sense to anyone else for you to be protected.

2. It also quietly admits something: theology doesn’t have to line up with shared logic. It can be self-contained. It can be mystery. It doesn’t have to be the same for everyone.

That’s fine for faith. But it’s a problem if we let the government use one group’s theology as the binding rule for everyone, especially on matters of life and death.

In a pluralistic country:

• Some people believe life (and full personhood) begins at conception, when there is a new genetic organism.

• Others (for example, many Jewish authorities) have religious interpretations where full human status comes later—tied to development, birth, or first breath.

• Still others, with secular ethics, focus on consciousness, capacity to feel pain, or other functional criteria.

The Constitution doesn’t ask any of us to give up our beliefs. It does, however, ask the state not to establish one theology as law.

So when the only reason to declare a one-cell zygote a full legal “person” is a theological conviction about ensoulment or divine command, the state has stepped out of neutral law and into religious enforcement.

That’s exactly what equal treatment and religious freedom were designed to avoid.

Religious freedom is precisely what makes space for moral disagreement: families and faith communities remain free to teach their own theology, to practice it, and to form their children within it. Within a home, belief can be guided—even insisted upon—by parental authority.

But the state does not have that license. Legislatures and courts have no business selecting a contested theological premise and converting it into a civil rule that treats citizens differently, especially where the justification depends on faith-claims that many reasonable citizens do not share and cannot evaluate using publicly accessible evidence and reasons.

Geraldine Ferraro—a self-described “devout Catholic” who said she “personally opposes” abortion—captured the constitutional boundary in simple terms: “I cannot force my religious views on someone else.” In a pluralistic republic, that is the line equal treatment and religious freedom were designed to hold.

With that boundary in mind—protected belief, but no state enforcement of theology—we can ask what a neutral starting point would look like.

5. A brain-based starting point: using one kind of rule at both ends

We don’t have to agree with each other on theology to agree on a modest civic principle:

The law should use the same kind of reasoning at the beginning of life that it already uses at the end.

At the end of life, American law commonly allows death to be determined by neurologic criteria—i.e., when there is an irreversible cessation of all functions of the entire brain, including the brainstem, as determined by accepted medical standards. (Important note: this determination is clinical; EEG can be supportive in limited contexts, but it is not “the test” by itself.)

A parallel starting point would be this:

Personhood begins no earlier than when the developing human has the basic neural structures and organized brain activity needed for any plausible capacity for consciousness or integrated mental life.

This doesn’t require us to pick a precise week in this essay. Clinicians and scientists can disagree about exactly when minimum thresholds are crossed, and reasonable citizens can disagree about what margin of caution to build into law.

What matters for the public conversation is that we acknowledge a difference between:

• A cluster of cells with no developed brain structures or organized brain activity.

• A fetus late in pregnancy with a functioning nervous system and increasingly complex brain organization.

Before viability, fetal survival depends entirely on continuous maternal–placental physiologic support—oxygenation and CO₂ removal via the placenta, metabolic and endocrine regulation, immune and nutritional support, and the pregnant woman’s whole-body homeostasis. Ending a pregnancy before viability therefore functions, in practical terms, as ending that physiologic support relationship.

And we should be honest about what it would mean to treat the fetus as a fully separate legal person from the earliest stages: it would impose a uniquely continuous, 24/7 affirmative duty of bodily support on one citizen to sustain another. Outside of narrow, well-defined circumstances (special relationships, custody, contract, or limited professional obligations), American law is typically reluctant to compel one person to provide life-sustaining aid with their body. Yet early full-personhood rules would do exactly that—while often leaving the biological father’s pregnancy-period obligations comparatively indirect, non-automatic, or dependent on separate legal steps.

So, at minimum, we can commit to this floor:

We will not treat a fetus prior to any organized brain activity plausibly supporting consciousness as having a fuller legal personhood than a human being who has been declared dead by neurologic criteria after previously having integrated brain function.

That’s the core of Cogito, Ergo Sum in legal terms: when we decide who is a “someone” under the law, the brain can’t be everything—but it also can’t be nothing.

Once we admit the law is already using brain-based reasoning at the end of life, the next question is whether the state can apply a different kind of reasoning at the beginning without violating equal treatment.

6. Equal protection: why this isn’t just philosophy

The Fourteenth Amendment says:

“Nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.”

So two questions matter:

• Who counts as a “person”?

• Are we treating “persons” consistently?

For decades, the Supreme Court read “person” in the Fourteenth Amendment as not including the unborn, which was part of the background for Roe. Dobbs changed the abortion-rights framework, but it did not declare embryos and fetuses to be Fourteenth Amendment persons. It handed the question back to states.

Here’s where consistency concerns come in:

If a state declares that a zygote is a “person” with full rights for abortion law, but:

• Doesn’t issue death certificates for early miscarriages.

• Doesn’t treat discarded IVF embryos as deaths of persons.

• Doesn’t store millions of frozen embryos as if they were a population of full citizens.

• Doesn’t include them in a census, or in population counting for construction of schools, firehouses, police stations, or other governmental functions.

Then it is effectively picking and choosing when that “person” status matters.

If a state says a person declared dead by neurologic criteria with a beating heart is not a person anymore, but an embryo with no developed brain structures is, it is using two different kinds of criteria for “person” without a neutral justification.

Equal protection doesn’t require the law to be perfect. But it does require:

• That the state have secular, public reasons for how it defines “person.”

• That similar cases be treated in similar ways.

Right now, in many arguments about conception and personhood, that consistency is missing.

None of this tells anyone what to believe; it only asks what the state may require all citizens to live under.

7. This isn’t about telling anyone what to believe

None of this requires anyone to abandon their faith.

• If you believe G_D ensouls a new human at conception, you can—and should—live by that belief in your own choices, your community, and your moral teaching.

• If your tradition places the key moral threshold later—at quickening, viability, birth, or first breath—you can live by that understanding too.

What we’re saying is narrower, and more civic:

When the government of a pluralistic republic makes law about life and death, it should adopt criteria that:

• Are logically coherent within the legal system.

• Can be explained in secular, publicly accessible reasons that don’t depend on any one theology being true.

We’ve already done something like this at the end of life, by recognizing death by neurologic criteria under accepted medical standards.

The invitation of Cogito, ergo sum here is simple:

• If thinking, consciousness, and brain function matter enough to tell us when a person is gone,

• then they should matter when we decide when a person begins.

People can still oppose abortion on many grounds. Many will continue to believe life is sacred from the first cell. But if we care about equal treatment under law, we should not pretend that a one-cell zygote and a person declared dead by neurologic criteria are obviously the same kind of legal “person” simply because both involve living human tissue.

The more serious we are about the sanctity of life, the more we should ask our laws to be honest and consistent about what—exactly—we mean by “life” and “person” at both ends of the human story.

8. What this argument does and doesn’t claim

This argument does not tell anyone what to believe about morality, theology, or the sacredness of life. It does not require anyone to abandon faith, or to stop teaching their children what their tradition holds.

It does claim something narrower and more civic: in a pluralistic republic, when the government makes law about life and death, it should rely on publicly accessible reasons and apply its criteria in a way that respects equal treatment under law.

And it asks one symmetry question the law cannot avoid forever:

If death can be recognized by the irreversible loss of the functions of the entire brain, including the brainstem, what principled reason justifies recognizing full legal personhood at a point when no brain yet exists—or no organized brain activity plausibly supporting consciousness has begun?

While it might have been better, I chose to end this piece with a bit of information about the author. I was born in the Summer of 1957 and surrender for adoption. The information provided me by the agency is my mother was an unwed teen from the South East United States and was sent to Florida to give birth. When I discuss abortion issues I fully understand and am always keenly aware that had abortion been as available in late 1956 to early 1957, the likelihood that I would be here to write this paper is near zero.

I'd also like to point out that even I don't always me on every issue where I want for myself something it is unfair to ask of others. It's a difficult thing to realize, but what would make me happiest is not always the best outcome for other people. Striking that balance is probably the most difficult thing for any of us to face, but face it we must if we are to live in a society where all are equal under the law.