100 hairs fall out of your head each day, and a hundred new ones begin to grow in. Every few days your stomach lining is entirely replaced, with brand new cells taking the place of ones that were shed. Every few weeks the outer later of your skin is replaced. Every four months all of your red blood cells are different, with 100 million new cells developing every minute. Every six months you have brand new fingernails. Every 5 years or so every hair on your head is different, every 10 years every cell of bone is different. Every 15 years all of your muscle tissue is replaced, and it takes 25 years for fat cells to be exchanged. Of the few things that remain unchanged throughout a lifespan, the only ones of note are about half the cells of the heart, the neurons of the brain, and the lens which forms the outer part of your eye.
However, a cluster of neurons, half a heart, and a viscous tissue through which we see the world hardly constitutes a full 'person.' If we are constantly in flux, if our bodies are always changing, developing, then who, ultimately are 'we.' Who is the 'I' that we reference when we use the first person? Who is the 'self' which we identify with our innermost essence as a person?
A simplistic theology would tell you that what makes 'you,' 'you' is the 'soul.' According to most of its proponents, the soul is an indivisible spiritual entity which defines your self and connects you to the realm of the spiritual. The whole notion on which our liberal humanist society is based - that each person has a 'individual,' indivisible soul - seems to be at odds with all of what we know about our bodies.
Our bodies change constantly, regenerate, replace, and eventually relinquish their hold on material existence. At some point entropy and aging overtake that drive to regenerate cells, and we begin to die. Yet, we're told, we can rest assured that the solid 'self' which lies within the soul lives on.
If that's true, then there are somewhere in the range of 107 billion souls out there, as that is the conservative estimate of how many human beings have ever lived. That means that for every person alive today on the earth, there are 15 people who have died during the course of history, each of which continued to exist in the form of a 'soul' after death. That of course, is assuming animals and other forms of life don't have our prized 'souls,' which I'm not sure I can say for sure. If we were to include all living things in our 'soul-count' or even all mammals, the numbers become inconceivable.
So how can we understand the idea of a 'soul' without feeling like it conflicts with everything we know about ourselves, about our changing bodies? One conception, which emerges from Jewish mysticism, offers some hope.
To the mystics, life after death involved what they termed gilgulé neshamot, or transmigration of souls. More or less this is a form of reincarnation. However, what's potentially radical and extremely useful to us skeptical moderns is that they included within their conception the idea that the soul was in fact a composite entity.
Like our bodies and its billions of cells and our planet and its billions of people, our soul, they argued, is made up of innumerable tiny fragments, pinpricks of divine light. They called these nitsotsot, sparks, and understood that the soul which we possess during our life is in fact a unique configuration of these soul-sparks. We have, for our short lifespan here on Earth, a special constellation of divine energy, amassed from broken shards of previous worlds and chips off the divine rock. When we die, the sparks that make up our particular soul separate and reconstitute. Some of them may rejoin together in the next life, some may not.
Thus, they are able to believe in reincarnation without having to explain why it is we don't remember past lives. We live many lives, but each one is a different configuration of soul-fragments. Each life is itself a composite entity, existing for a short period of time and then remerging into a greater fabric of divine light. They suggest that these sparks actually do fall into groups, that they are shattered bits of primordial souls. Thus, they explain that the things we are drawn to, the people we are drawn to-- often hold such extraordinary sway over us because some bit of our soul is magnetically drawn to a similar bit in someone else. A little bit here, a little bit there; Regenerating, replacing, reincarnating.
I think this may be the best way for us as modern people to understand our 'selves.' We do have souls, but they aren't so special or unique to some essential version of 'us.' I am who I am because of the unique configuration of sparks which happens to make up the soul I currently possess.
Thus, when we mourn someone who has died, we mourn their soul. What a special configuration of sparks that person was! Just enough of this, a little bit of that; The combination was excellent. That specific combination may in fact never be seen again, but we can nonetheless take some solace in knowing that the sparks which made up that unique soul will be re-used, perhaps have already been re-used. Maybe you recognize some bit in a relative, in the face of a stranger, or in the sound of the wind rustling through the trees. Wherever we go, we are surrounded by soul-sparks, new and old, familiar and strange, ones we have been and ones we have yet to be.
One way to think about this is, of course, through stories. As we turn to Yizkor, I hope we can explore this idea of composite soul-sparks. Perhaps this story from David Eagleman's brilliant work Sum: Forty Tales from the Afterlives can help illustrate the idea in a different way:
"When soldiers part ways at war’s end, the breakup of the platoon triggers the same emotion as the death of a person-- it is the final bloodless death of the war. This same mood haunts actors on the drop of the final curtain: after months of working together, something greater than themselves has just died. After a store closes its doors on its final evening or a congress wraps up its final session, the participants amble away, feeling that they were part of something larger than themselves, something they intuit had a life even though they can’t quite put a finger on it.
In this way, death is not only for humans but for everything that existed.
And it turns out that anything which enjoys life enjoys an afterlife. Platoons and plays and stores and congresses do not end-- they simply move on to a different dimension. They are things that were created and existed for a time, and therefore by the cosmic rules they continue to exist in a different realm.
Although it is difficult for us to imagine how these beings interact, they enjoy a delicious afterlife together, exchanging stories of their adventures. They laugh about good times and often, just like humans, lament the brevity of life. The people who constituted them are not included in their stories. In truth, they have as little understanding of you as you have of them; they generally have no idea you existed.
It may seem mysterious to you that these organizations can live on without the people who composed them. But the underlying principle is simple: the afterlife is made of spirits. After all, you do not bring your kidney and liver and heart to the afterlife with you-- instead, you gain independence from the pieces that make you up.
A consequence of this cosmic scheme may surprise you: when you die, you are grieved by all the atoms of which you were composed. They hung together for years, whether in sheets of skin or communities of spleen. With you death they do not die. Instead, they part ways, moving off in their separate directions, mourning the loss of a special time they shared together, haunted by the feeling that they were once playing parts in something larger than themselves, something that had its own life, something they can hardly put a finger on."