1. When did your life begin?
To answer this question, we must first discuss the definition of life and the definition of person. For millennia, people have recognized that life is special and unique compared to inanimate objects. Biology, the study of life, has entranced many minds throughout history, but it wasn't until the 16th and 17th centuries that biology's popularity exploded from the development of the scientific method and the discovery of cells.
The cell is the designated smallest unit of life because it meets 7 main criteria: organized structure, metabolism, growth, response to stimuli, homeostasis, reproductive capability, and evidence of adaptation through evolution. Cells are living things that compose all living things on our planet—bacteria, plants, animals, and people. You, as a person, are composed of trillions of these individual lives, and by working together harmoniously, these lives within you each perform specific functions to support your life. According to biology, you are alive, and each cell working to keep you alive is alive.
At the smallest level, it is important to note that life doesn’t actually begin; it continues. Cells can merge together, and cells can divide themselves. But neither of these two events is a clear beginning or end of a particular cell's life. When cells merge or divide, it would be a stretch to say that a “completely new cell” exists. This is why scientists agree that, in general, life is a continuum.
While scientists agree that life is a continuum, it is also a fact of our world that all living things eventually die. Looking at the smallest unit of life, we know cells die in four main ways: they can die when destroyed by physical forces; they can die when attacked by other cells (or viruses); they can die from senescence (the cell version of old age); and they can die from apoptosis (the cell version of suicide). Within your body, cells die every day, and yet you are still here. This means that your life, as a person, is something beyond the existence of each of your cells.
If you ask a child, “What is a human life?”, he may point at you, or at himself. If you ask a biologist, “What is a human life?”, she may tell you that each living cell within you is a human life because each cell is alive and each cell functions from the instructions of human DNA. You, as a person, are technically comprised of trillions of human lives! Believe it or not, human life and personhood are not one and the same. Because the average person does not hold a Ph.D. in both Biology and Philosophy, it's not surprising that people tend to conflate “human”, which is biological, with “person”, which is philosophical. Unfortunately, this causes confusion when people talk about abortion. Confusion causes frustration, frustration causes anger, and anger between two groups of people leads to trouble.
The truth is that the concept of personhood isn't biological. It's philosophical. The video below can give you a crash course on the philosophy of personhood. The narrator, Hank (co-founder of the educational channel Crash Course), clearly and impartially describes the difference between human life and personhood . . . hear for yourself by enjoying the video below.
Did you watch the video? If not, know that it's less than 10 minutes long and very informative— definitely worth watching later if you have time. To recap, the definitions of personhood reviewed by Hank are Noonan’s Genetic Criterion, Warren’s 5 Criteria, the Social Criterion, Singer’s Sentience, and the Gradient Theory of Personhood. But none of these specific definitions of personhood have been able to settle the tension between Pro-Life and Pro-Choice groups. So, Respect People offers you a different definition.
After watching Hank's Crash Course on Personhood, you should understand that human life and personhood are distinct concepts. While each living cell within you is a human life, only you, as the sum of the coordinated function of those human lives, are a human person. This means that the life of any one of your cells and your life, as a person, are two different things. For example, have you ever considered how your future death is not simultaneously the death of all the cells in your body? After your death, cells within the body you left behind can live for days, and certain cells can live for more than two weeks after you're gone, until they run out of energy to consume, since you are no longer there to control that body and eat to provide those cells with nutrients. If you die and become an organ donor, some of the cells with your DNA will live for much longer than two weeks after your passing. Indeed, cells with your exact DNA, that used to be a part of you, can live on within, reproduce within, and be a part of another person. You need your cells, but your cells don't necessarily need you!
Here's the point: If the end of your life is not congruent to the death of all cells with your DNA, then it is reasonable to consider that the beginning of your life is also not congruent to the rise of new cellular life with your DNA. Therefore, to answer the question "When did your life begin?", you must ask yourself what distinguishes your life from the trillions of cellular lives that support you?
We have thought hard about this question, and we arrived at an answer: While we and our cells both have human DNA and meet the 7 criteria for biological life, we, as people, meet 2 additional criteria: we can think thoughts and feel emotions! Thus, Respect People defines a human person as a life form that meets the 7 criteria of life (organized structure, metabolism, growth, response to stimuli, homeostasis, reproductive capability, and adaptation through evolution) plus 3 more criteria specific to human people (a human genome, the ability to think thoughts, and the ability to feel emotions) for a total of 10 criteria. We call this definition the Ten Criteria for Human Personhood.
The process of differentiating persons from non-persons can be simplified by acknowledging that the ability to think thoughts and feel emotions occurs from within one specific organ: the brain. Your brain, a magnificent organ, is what permits your life to be extraordinary compared to cellular life. When your brain ceases to function—that is, when your brain ceases to have the ability to think thoughts and the ability to feel emotions—your life as a person ends. Likewise, when your brain gained this function—that is, the ability to think thoughts and feel emotions—your life as a person began.
After hearing the Ten Criteria for Human Personhood for the first time, some people ask, "How do the Ten Criteria measure up to an unconscious person?" The simple answer is that the ability to think thoughts and feel emotions is not the same as consciousness. For example, you can think thoughts and feel emotions while dreaming, but while dreaming you aren't conscious. Furthermore, there is a difference between having an ability and actively using that ability. For instance, someone who has the ability to sing like an angel still has that ability even when they're simply relaxing on a couch and watching TV instead of singing. There is also a difference between having an ability and having a memory of using that ability. Case in point, we do not have memories of every single thought and emotion from when we were two years old, but the fact that we don't remember does not negate the fact that we did have the ability to think thoughts and feel emotions when we were toddlers. This distinction affirms that infants are indeed people (and answers the question, "How do the Ten Criteria measure up to infants?"). Likewise, an unconscious person may not remember many thoughts or emotions from the time they were unconscious, just like a person may not remember all of the dreams they had last night, but not remembering is not proof that thoughts were not thought and emotions were not felt. This distinction also affirms that people who have Alzheimer's are, in fact, still people. In summary, the ability to think thoughts and feel emotions is a characteristic of all indisputable people because a) it's not contingent on consciousness, b) it's not contingent on active use, and c) it's not contingent on memory of use. What it is contingent on, however, is having a brain. For as long as a person is not brain dead or severely brain-damaged, they'll have the ability to think thoughts and feel emotions. Ultimately, the Ten Criteria for Human Personhood is a simple but useful philosophical standard to differentiate persons from non-persons. If a living thing does not have the ability to think thoughts and feel emotions, it is not a person.
Now that we've discussed the definitions of life and person, and now that we've recognized that the difference between a person and a non-person life form is that a person has the ability to think thoughts and feel emotions, we finally can answer the question "When did your life begin?" by investigating when a developing brain gains the ability to think thoughts and feel emotions.
Image Credit: TheVisualMD/Science Source
Extraordinary amounts of time and research have been devoted to mapping the timeline of human brain development and to distinguishing which parts of the brain are necessary for thinking thoughts and feeling emotions.
A great place to start learning about the timeline of fetal brain development is this short excerpt from Dr. Michael S. Gazzaniga's book, The Ethical Brain. Dr. Gazzaniga is the Director of the SAGE Center for the Study of Mind at the University of California, Santa Barbara. If for some reason you cannot access the excerpt from the link above, you can access the excerpt in The Ethical Brain's free book sample provided on Amazon.
Another excellent short read about the timeline of fetal brain development is "When Does Consciousness Arise in Human Babies?", a Scientific American magazine article by Dr. Christof Koch, a chief scientist at the Allen Institute for Brain Science.
The Human Brain Book: An Illustrated Guide to its Structure, Function, and Disorders is a fabulous resource to learn about which-parts-of-the-brain-contribute-to-what as well as basic information on brain development and aging. If you loved going to science museums as a kid, you'll love the illustrations in this book.
Some technical readings that discuss fetal brain development include The thalamus: gateway to the mind by Lawrence M. Ward; Can fetuses feel pain? by Stuart W. G. Derbyshire; Fetal Pain: A Systematic Review of the Evidence by Lee, Ralston, and Drey; Fetal Awareness: Review of Research by The Royal College of Obstetricians and Gynaecologists; and Decoding the neuroscience of consciousness by Emily Sohn.