Apr 9th 2016

What Is Life?

by Jeff Schweitzer

Jeff Schweitzer is a scientist and former White House Senior Policy Analyst; Ph.D. in marine biology/neurophysiology

Zombies and the walking dead make for good copy, but do little to advance our understanding of life and death. Unfortunately, neither did the National Geographicwith a cover article entitled, “The Science of Death: Coming Back from the Beyond.”

The article issues forth just about every misconception of life that permeates our national discussion. Sam Parnia, a critical care physician and author of the book Erasing Death, is quoted as saying that death “is a process, not a moment.” So far so good. But then he makes a common but critical error in thinking, which gets to the heart of our problem. In discussing a victim of a whole body stroke, Parnia writes that the patient’s organs can continue to function for a period after the heart stops beating. From this he concludes that “for a significant period of time after death, death is in fact fully reversible.”

Well, no, it is not. If a patient can be revived, the patient was never dead in the first place. But how can that be if we see no brain waves and the heart has stopped beating? Surely that is dead, isn’t it? If someone was revived from that state, clearly we must say he came back from the dead, no? That is certainly what is commonly believed, but no, we can’t. The success of reviving the victim means that during that state in which it seemed as if biological functions ceased, the functions essential for life in fact remained viable enough to be resuscitated — and therefore the patient never died. Reports of Mark Twain’s death were exaggerated only because he was not dead. The same is true for “miracles” like toddler Gardell Martin who was “dead” for an hour and a half after falling into an ice-cold stream. We are very happy to have him among the living, but he never left us in the first place.

We find this curious state of suspended animation difficult to accept as anything other than dead because we are asking the wrong question about life and death, without ever clearly defining what it means to be alive. Most of us hold deeply and unquestioned the idea that life is all-or-nothing , on or off, live or dead, one or the other, black and white. I mean, something is either alive or dead, end of story. Nothing could be further from the truth.

We are in good company in failing to define life. Dating back to the early Greeks and across millennia to modern times, great minds have recoiled from the notion that life might be a matter of degree, because our intuition so strongly demands that something be alive or not. But our intuition serves us poorly here. The problem seems to be that the more rigorously we attempt to define life, the more we encounter ambiguous cases that test our assumptions, stretch the limits of our definitions, and demonstrate where intuition and common sense falter. With even casual observation, the essence of what makes something alive quickly becomes non-intuitive when we are presented by forms that defy easy categorization such as bacterial spores or crystallized virus capsules that can rest inert for centuries before being reanimated. Those viruses would appear to be no more alive than a pile of salt, but we know that only one can be re-introduced into the kingdom of the living.

Iron is Iron

History has failed to give us a good definition of life precisely because life was viewed not as this continuum from inanimate to animate, but as a huge leap from one to the other. To be alive meant having a special essence, something beyond the normal mechanisms that governed inorganic chemistry and physics. Invoking “vital forces” to explain life endures today in much of the general public. But vitalism, this endowing the living with a life force, is tautological, and explains nothing. If something is alive, it must have a life force; if it is dead, a life force must be absent. That is circular, not helpful.

We now know that no life force exists. The laws of physics and chemistry are indifferent to our struggle to define life, and operate identically on the same principles whether we deem something to be living or dead. The carbon, nitrogen, phosphorous, iron and other atoms that come together to form our bodies are just that: the same elements that are found in the iron skillet in our kitchens and the nitrogen in the soil fertilizing our gardens. The atoms in our bodies are not special or endowed with any properties different from the atoms in every object around us. Iron is iron is iron, whether attached to hemoglobin in our blood or flaking off the hull of a rusting ship.


A continuum describes a whole, no part of which can be distinguished from neighboring parts except by arbitrary division. The best example is visible light. You know without hesitation when something is green or blue, but cannot say exactly when one color yields to the next. Any attempt to define where one color ends and the other begins becomes arbitrary because green turns to blue across a smooth gradient of frequencies with no inherent boundaries. A pristine lake might be green-blue or blue-green or turquoise, but not clearly green or blue. This nature of the light applies to the idea of living and non-living as well. If we call green “dead” and blue “alive” we see that no boundary exists between the two because they transition one to the other with no intervening gap.


Atoms deserve special attention since everything we know is an aggregation of atoms, the same in things dead or alive. The simplest and lightest atoms such as hydrogen, helium, and some lithium formed just moments after the Big Bang. A star derives energy from the combining of these lighter elements into heavier elements through nuclear fusion. Our own Sun is currently fusing hydrogen to helium, a process that will occupy most of its lifetime. After the hydrogen supply is depleted, the star will burn helium to form progressively heavier elements such as carbon, oxygen, silicon, sulfur, and iron. Up to a point, fusion releases energy and is therefore self-sustaining, which is why we see the sun shining every morning, unless you live in Seattle.

This all relates to life; just hold on a few more seconds. The creation of elements heavier than iron requires the input of energy, and is not self-sustaining. Some other source of energy is needed, and that comes from the explosion of a supernova. A massive star will eventually deplete its energy source of lighter elements. The star will collapse into itself when no longer supported by the release of nuclear energy through fusion. If the original star was sufficiently massive, the collapse will release a huge amount of energy in a spectacular explosion. The resulting supernova supplies the energy necessary to support fusion of nuclei heavier than iron. The explosion also causes a blast wave that ejects the elements into interstellar space. Some of this dust is eventually gathered up in planets, like earth, as new solar systems form. Every single carbon atom in your body, and every carbon atom in the charcoal at the bottom of your barbecue, comes from such interstellar dust.

Nothing Special

Derived from stardust, the elements in your body exhibit no special properties. Carbon is carbon. Nitrogen is nitrogen. Atoms are just atoms, so the old premise that life is made of some special stuff is wrong. But more modern efforts to describe life fall short, too. The most recent edition of the Encyclopaedia Britannica offers a typical definition of life as a “state characterized by the ability to metabolize nutrients (process materials for energy and tissue building), grow, reproduce, and respond and adapt to environmental stimuli.” At first, that sounds perfectly reasonable, but the Britannica definition is in fact completely inadequate, as has been every previous attempt.

The Characteristics of Life

Broadly speaking, the following characteristics are usually invoked in various orders and degrees to define life: autonomy; reproduction; stability, change and evolution; resistance to entropy; conversion of matter and energy; metabolism; excretion; movement; autopoiesis; homeostasis; complexity; organization; growth and development; respiration; responsiveness; the presence of a genetic code. The fatal flaws in each of these characteristic called upon to define life all fall into just three simple categories: the traits assigned to life are present in some non-living systems (like growth, in crystals), the traits assigned to life are absent in some living systems (movement - think of sponges), or the traits can only be determined or defined across generations (like evolution or reproduction), depriving us of the ability to determine if the beast before us is alive or not. Every single character or trait that has been used to define life suffers from one or more of these three deficiencies.

Take the presence of a genetic code for example. That would seem to be a pretty good way of defining life because DNA is only found in living things. Wrong. We can extract DNA from fossils, and few would argue that an old bag of bones that has been in the ground for 100,000 years is alive. This type of defect in definition can be found in every one of those categories that so many have invoked to define life.

Beautiful Ambiguity

Let’s return to the idea of colors. Nobody would deny the existence of green or blue, yet nobody can define when one color becomes the other. That inability to draw a clear line between them does not diminish the reality of the two colors. We accept the existence of clearly identified colors even when the transition between colors of light are absent of any clearly delineated boundary. Life is no different. We know at the extremes when something is alive or not, with no ambiguity, just as we know something is green or blue. Other cases are ambiguous, just as we do not know when green becomes blue. A virus could be alive or not, simply depending on your perspective. In some cases, such as viruses, bacterial spores, and prions, defining matter as alive or not becomes arbitrary, an exercise in semantics, rather than a window into the deeper workings of nature. We might be obsessed with attaching a label of “living” to something, but that something simply sits somewhere along a continuum of complexity regardless of the label finally affixed, aloof to our discomfort.

The region along the spectrum of complexity where non-living transitions to living is a zone of ambiguity that exists because life is not an all-or-none phenomenon, and because the stuff of life is the same stuff as non-life. Previous definitions of life have fallen short because of a common commitment to find a unique spark that simply does not exist. Definitions struggled to capture something essential about life that was not found in the non-living world, rather than accept that no such distinction can be found. Definitions of life were meant to reflect something fundamental about nature, rather than serve as a useful tool for categorizing complexity. That is why all have failed.

There is no single unambiguous definition of life. Most examples of life are complex; most metabolize, grow, reproduce, and evolve over time. But not all do, and not all have all of these functions present. Some physical systems also share these same characteristics. That fact is not troubling; it reflects the reality of nature. “Life” is an arbitrary label we apply to distinguish extremes of complexity along a continuum. We know that a block of pure quartz is not alive and that a screeching kid in the restaurant is; whatever label we paste on all those cases in between is a convenient convention, but in no way reflects any fundamental break or division between the living and non-living.

These thoughts are not original, just widely ignored by those outside the field of biology. Josephine Marquand suggested in 1968 that we “avoid the use of the word ‘life’ or ‘organism’ in any discussion of borderline systems.” Norman Horowitz in 1955 and John Keosian in 1964 concluded much the same as here. Even the 1968 Encyclopaedia Britannica stated that “There is no point along the continuum of existence from the simplest atom to the most complex animal, at which a line can be drawn separating life from nonlife.” Notice, however that Marquand, Horowitz and Keosian are not household names, nor is the Britannica observation widely cited. The idea of a continuum of complexity, with simple inorganic systems at one end and the highest life forms at the other, is a bit difficult to digest, and does not satisfy the human need for easy answers. The idea also moves against the grain of our intuition about something being alive or not. So we put up some resistance. But resistance is futile.

With a new perspective on the phenomenon of life, we can look with a more jaundiced eye at claims of death and resurrection in cases like Gardell Martin. We can readily reject statements like “death is in fact fully reversible” when we know that life is a continuum along a spectrum of complexity, with no simple on-off switch. Those revived were never dead, the switch was never turned off - just dimmed to below our ability to see, waiting to be re-energized. Let’s move away from this rather silly idea of victims coming back from “the beyond” and leave Zombies, the walking dead and resurrection to Hollywood and Sunday sermons. You can’t come back from a place you’ve never been.

Dr. Jeff Schweitzer is a marine biologist, consultant and internationally recognized authority in ethics, conservation and development. He is the author of five books including Calorie Wars: Fat, Fact and Fiction (July 2011), and A New Moral Code (2010). Dr. Schweitzer has spoken at numerous international conferences in Asia, Russia, Europe and the United States.Dr. Schweitzer's work is based on his desire to introduce a stronger set of ethics into American efforts to improve the human condition worldwide. He has been instrumental in designing programs that demonstrate how third world development and protecting our resources are compatible goals. His vision is to inspire a framework that ensures that humans can grow and prosper indefinitely in a healthy environment.Formerly, Dr. Schweitzer served as an Assistant Director for International Affairs in the Office of Science and Technology Policy under former President Clinton. Prior to that, Dr. Schweitzer served as the Chief Environmental Officer at the State Department's Agency for International Development. In that role, he founded the multi-agency International Cooperative Biodiversity Group Program, a U.S. Government that promoted conservation through rational economic use of natural resources.Dr. Schweitzer began his scientific career in the field of marine biology. He earned his Ph.D. from Scripps Institution of Oceanography at the University of California, San Diego. He expanded his research at the Center for Learning and Memory at the University of California, Irvine. While at U.C. Irvine he was awarded the Science, Engineering and Diplomacy Fellowship from the American Association for the Advancement of Science.Dr. Schweitzer is a pilot and he founded and edited the Malibu Mirage, an aviation magazine dedicated to pilots flying these single-engine airplanes. He and his wife Sally are avid SCUBA divers and they travel widely to see new wildlife, never far from their roots as marine scientists..To learn more about Dr Schweitzer, visit his website at http://www.JeffSchweitzer.com.

To follow Jeff Schweizer on Twitter, please click here.

For Jeff Schweitzer web site, please click here.

Below link to Amazon for Jeff Schweitzer's latest book.



This article is brought to you by the author who owns the copyright to the text.

Should you want to support the author’s creative work you can use the PayPal “Donate” button below.

Your donation is a transaction between you and the author. The proceeds go directly to the author’s PayPal account in full less PayPal’s commission.

Facts & Arts neither receives information about you, nor of your donation, nor does Facts & Arts receive a commission.

Facts & Arts does not pay the author, nor takes paid by the author, for the posting of the author's material on Facts & Arts. Facts & Arts finances its operations by selling advertising space.



Browse articles by author

More Essays

Jun 17th 2021
EXTRACT: "Confronting our complex history and ultimately embracing a more equitable, balanced, and humble culture may be a tall order in these fractious times. But that makes it even more imperative that we fully reckon with who we are and who we are capable of becoming."
Jun 11th 2021
EXTARCT: "A further health benefit of hiking is that it’s classed as “green exercise”. This refers to the added health benefit that doing physical activity in nature has on us. Research shows that not only can green exercise decrease blood pressure, it also benefits mental wellbeing by improving mood and reducing depression to a greater extent than exercising indoors can."
Jun 10th 2021
EXTRACT: "“The greatness of a nation and its moral progress,” Mahatma Gandhi said, “can be judged by the way its animals are treated.” If we apply that test to the world as a whole, how much moral progress have we made over the past two millennia? ...... That question is suggested by The Golden Ass, arguably the world’s earliest surviving novel, written around 170 CE, when Emperor Marcus Aurelius ruled the Roman Empire. Apuleius, the author, was an African philosopher and writer, born in what is now the Algerian city of M’Daourouch."
Jun 4th 2021
EXTRACT: "Research we’ve done, which looked at 37 adults with type 2 diabetes, found that over two weeks, prolonged sitting was associated with high blood sugar levels. But we also found that when people stood up or walked around between periods of sitting, they had lower blood sugar levels. Other studies have also had similar results."
May 28th 2021
EXTRACT: "Paul Van Doren's legacy lies in a famous company, and in his advice to young entrepreneurs to get their hands dirty, and to know what goes into making what they are selling."
May 19th 2021
EXTRACT: "May 7th marked three hundred and ten years since the philosopher David Hume was born. He is chiefly remembered as the most original and destructive of the early modern empiricists, following John Locke and George Berkeley." .... " Shocking as it may (and should) sound, Hume is implying nothing less than that the next time you turn the key in your car ignition, you are as justified to expect the engine will start as you are in believing it will turn into a pumpkin. For there is a radical contingency that pervades all our experience. We could wake up tomorrow to a world that looks and behaves very differently to the one we are in now. Matters of fact are dependent on experience and can never be known a priori — they are purely contingent, and could always turn out different than what we expect."
May 1st 2021
EXTRACT: " The sad reality is that the Mizrahim (Jews of Middle Eastern and North African descent) were discriminated against from the day of Israel’s inception, whose Ashkenazi (European Jewish) leaders viewed them as intellectually inferior, “backward,” and “too Arab,” and treated them as such, largely because the Ashkenazim agenda was to maintain their upper-class status while controlling the levers of power, which remain prevalent to this day." ..... " The greatest heartbreaking outcome is that for yet another generation of Israelis, growing up in these debilitating conditions has a direct effect on their cognitive development. A 2015 study published in Nature Neuroscience found that “family income is significantly correlated with children’s brain size…increases in income were associated with the greatest increases in brain surface area among the poorest children.” "
Apr 25th 2021
EXTRACT: "We all owe Farah Nabulsi an enormous debt of gratitude. In a short 24-minute film, The Present, she has exposed the oppressive indecency of the Israeli occupation while telling the deeply moving story of a Palestinian family. What is especially exciting is that after winning awards at a number of international film festivals​, Ms. Nabulsi has been nominated for an Academy Award for this remarkable work of art. " 
Apr 25th 2021
EXTRACT: "When I crashed to the floor of my home in Bordeaux recently after two months of Covid-19 dizziness, I was annoyed. The next day I collapsed again. Now I was worried. What I didn’t know was that my brain was sloshing around inside my skull, causing a mild concussion. Nor did I know that I was in for a whole new world of weird and wonderful hallucinations."
Apr 13th 2021
EXTRACT: "Overall, our review has found that there isn’t evidence to back up the claims that veganism is good for your heart. But that is partly because there are few studies ....... But veganism may have other health benefits. Vegans have been found to have a healthier weight and lower blood glucose levels than those who consume meat and dairy. They are also less likely to develop cancer, high blood pressure and diabetes. "
Apr 8th 2021
EXTRACT: "Pollock’s universe, the universe of Mural, cannot be said to be a rational universe. Nor is it simply devoid of all sense. It is not a purely imaginary world, although in it everything is in a constant state of flux. Mural invokes one of the oldest questions of philosophy, a question going back to the Pre-Socratic philosophers Parmenides and Heraclitus – namely, whether the nature of Reality constitutes unchanging permanence or constant movement and flux. For Pollock, the only thing that is truly unchanging is change itself. The only certainty is that all is uncertain."
Apr 8th 2021
EXTRACT: "Many present day politicians appear to have psychopathic and narcissistic traits too. It’s easy to spot such leaders, because they are always authoritarian, following hardline policies. They try to subvert democracy, to reduce the freedom of the press and clamp down on dissent. They are obsessed with national prestige, and often persecute minority groups. And they are always corrupt and lacking in moral principles."
Apr 6th 2021
EXTRACT: "This has led some to claim that not just half, but perhaps nearly all advertising money is wasted, at least online. There are similar results outside of commerce. One review of field experiments in political campaigning argued “the best estimate of the effects of campaign contact and advertising on Americans’ candidates choices in general elections is zero”. Zero!"
Mar 30th 2021
EXTRACT: "The Father is an extraordinary film, from Florian Zeller’s 2012 play entitled Le Père and directed by Zeller. I’m here to tell you why it is a ‘must see’." EDITOR'S NOTE: The official trailer is attached to the review.
Mar 28th 2021
EXTRACT: "Picasso was 26 in 1907, when he completed the Demoiselles; de Kooning was 48 in 1952, when he finished Woman I.  The difference in their ages was not an accident, for studies of hundreds of painters have revealed a striking regularity - the conceptual painters who preconceive their paintings, from Raphael to Warhol, consistently make their greatest contributions earlier in their careers than experimental painters, from Rembrandt to Pollock, who paint directly, without preparatory studies."
Mar 26th 2021
EXTRACT: "Mental toughness levels are influenced by many different factors. While genetics are partly responsible, a person’s environment is also relevant. For example, both positive experiences while you’re young and mental toughness training programmes have been found to make people mentally tougher."
Mar 20th 2021

The city of Homs has been ravaged by war, leaving millions of people homeless an

Mar 20th 2021
EXTRACT: "There are two main rival models of ethics: one is based on rights, the other on duties. The rights-based model, which traces its philosophical origins to the work of John Locke in the 17th century, starts from the assumption that individuals have rights ....... According to this approach, duties are related to rights, but only in a subordinate role. My right to health implies a duty on my country to provide some healthcare services, to the best of its abilities. This is arguably the dominant interpretation when philosophers talk about rights, including human rights." ........ "Your right to get sick, or to risk getting sick, could imply a duty on others to look after you during your illness." ..... "The pre-eminence of rights in our moral compass has vindicated unacceptable levels of selfishness. It is imperative to undertake a fundamental duty not to get sick, and to do everything in our means to avoid causing others to get sick. Morally speaking, duties should come first and should not be subordinated to rights." ..... "Putting duties before rights is not a new, revolutionary idea. In fact it is one of the oldest rules in the book of ethics. Primum non nocere, or first do no harm, is the core principle in the Hippocratic Oath historically taken by doctors, widely attributed to the ancient Greek philosopher and physician Hippocrates. It is also a fundamental principle in the moral philosophy of the Roman statesman Marcus Tullius Cicero, who in De Officiis (On Duties) argues that the first task of justice is to prevent men and women from causing harm to others."
Mar 18th 2021
EXTRACT: "Several studies have recently compared the difference between antibodies produced straight after a coronavirus infection and those that can be detected six months later. The findings have been both impressive and reassuring. Although there are fewer coronavirus-specific antibodies detectable in the blood six months after infection, the antibodies that remain have undergone significant changes. …….. the “mature” antibodies were better at recognising the variants."
Mar 15th 2021
EXTRACT: "Like Shakespeare, Goya sees evil as something existing in itself – indeed, the horror of evil arises precisely from its excess. It overflows and refuses to be contained by or integrated into our categories of reason or comprehension. By its very nature, evil refuses to remain within prescribed bounds – to remain fixed, say, within an economy where evil is counterbalanced by good. Evil is always excess of evil." ....... "Nowhere is this more evident than in war. Goya offers us a profound and sustained meditation on the nature of war ........ The image of a Napoleonic soldier gazing indifferently on a man who has been summarily hanged, probably by his own belt, expresses the tragedy of war – its dehumanization of both war’s victims and victors."