During the second week, the nuns followed with fascination the narrative of Darwinian evolution. The idea that species are not fixed, but change with time, was reasonable to them. But at the end, it was Khyentsee Yangsi Rinpoche who had his say. Something, very important, was missing in our theory of evolution: the notion of karma.

In Buddhist teaching, karma is the law of causality for all sentient beings’ moral actions. One accumulates karma, negative and/or positive, throughout one’s life, which is in turn determined by the karmic experience of previous lives. A certain number of positive actions will prove profitable in future lives, and negative thoughts and actions will have harmful consequences on future reincarnations.

I had to respond that the science I knew could not include the concept of reincarnation, and as a result, the concept of karma was foreign to it. He and the nuns took note of my words in silence. I continued my lesson by reminding them that, according to classic Darwinism, and therefore to modern science, all living beings derive from an initial population of primordial bacteria, the single-celled organisms that we had discussed the week before.

The evolutionary changes occur as a result of the need to create balance between the internal organization of the organism and the stress created by the changing environment. Yes, they kept interrupting, but what is the motivation for those changes? And I had to repeat time and time again that these changes were not taking place due to the conscious motivation of the organism, but that it was, in fact, a mechanism of ‘‘natural selection,’’ a kind of mechanical biology. The body is cognitive and recognizes its environment, and knows how to adapt in order to survive, but not because it is aware of what is doing. They remained unconvinced. I realized that to them, motivation should always be present no matter what, due to the mind and consciousness of the living organism itself. I knew that on this specific topic, we would never be in agreement.

I could not do much about genetics and the corresponding molecular biology, as they simply did not have the notion of “molecule”—something that for us, interestingly enough, is fundamental to all life science. But they responded favorably to the colored double helix which replicated non-linearly, despite my warning that these were cartoons that should not be taken too literarily. I also told them that, contrary to some cheap western news literature, the DNA gene did not “decide” to replicate, or to encode a protein. The message, the order, was given in response to a need by the whole living organism; it was a top-down approach. This explanation satisfied them.

Finally, I showed them the tree of life, and explained that, according to our Darwinian view, all living things on Earth, including plants and fish and microbes and birds, are all just one big living family, joined together by the thin, invisible thread of time and the evolutionary mechanism of genetic replication. And all of these organisms, from the smallest microbes to creatures as large as the elephant, from the sunflower to the trout living in lakes, share the same molecules, and the same biochemical mechanisms. I could see from their faces that the nuns readily accepted this scenario of unity and universal network, that it accorded with their spiritual views.

But then I had to add that, according to the common view of evolution biologists, and the corresponding notion of contingency as epitomized by Stephen Jay Gould and Mayr, nature and evolution do not have a predetermined plan. It was not prescribed a priori to have on our Earth yellow bananas, or green lizards, or forty thousand different species of butterfly. In fact, everything that exists and was formed by evolution could have been different, or not exist at all, depending on the conditions present during the evolutionary process. I said that, on this basis, humankind might not have arisen on Earth if conditions had been different.

This idea was completely foreign to them. The nuns accepted this possibility as part of our science, but they it clearly disturbed them. In the time allotted for the written exercise, I asked them to confront this view with the main tenet of Buddhism: “there is this, because there is that; and that is not, because this is not…”. Having spoken about what life really is from a scientific standpoint, I tackled the next logical question: what is death for science? I began by saying that all forms of life and non-life on earth are made by atoms, and since on earth there are no new atoms (apart from a little stardust that comes from the cosmos), all existing things must be composed of atoms, molecules, and atomic groupings that have already been used thousands and thousands of times for different things before. Death and life result as a continuous recycling of molecules. I added that in my body I could have atoms that belonged to some dinosaur that existed one hundred million years ago, and that the nun sitting in front of me may have atoms or molecules in her body that belonged to Marilyn Monroe...

Death is, therefore, a prerequisite of life itself. Molecular material is necessary to create new forms of life. As an exercise, we followed the imaginary path of a molecule belonging to a banana leaf, grown in India a million years ago. A bird eats the leaf, and then flies very far. A hunter eats the bird, and then dies at war in China, etc. The original molecule ends up in a Chinese tree. Every human being is composed of billions of atoms, each one with a long, adventurous history. All this aligned very well with their basic concept of impermanence: Anicca, in Pali, or Anytia in Sanskrit, one of the fundamental aspects of classic Buddhism, which says ‘Nothing is eternal, everything that is born must die...’

Here again, at tea time, there was a confrontation with the Rinpoche, who began to speak, looking up from his colorful teacup, ‘‘In this way, modern science accepts reincarnation. In fact, you said that perhaps a few million years ago you were a dinosaur, then a stone, then a fish.’’ ‘‘No,’’ I hastened to answer. ‘‘I did not say that I was a dinosaur or a fish, but some of the atoms and molecules present in my body were perhaps part of those animals. In our modern science, we believe that with the death of a man, one loses every trace of individuality. Nothing remains except the inanimate molecules, which are fragmented in pieces or atoms and reused in different bodies. In your concept of reincarnation, instead, there is the memory of a human being, a trace of the individuality of the person who dies.’’

The concept of reincarnation is a clear dividing line between classic science and Tibetan Buddhism. And for many Buddhists, those who do not accept that reincarnation exists are ignorant. I asked the Rinpoche provocatively, “You say that in Buddhism there is no I. Who, then, is reincarnating?” He turned my question, smiling, to an old monk I had grown fond of, the octogenarian Changdzo Ngodrup. Ngodrup was acting as the treasurer for the nunnery, and was famous for having built many monasteries in Tibet and Bhutan. His eyes were of a very intense, baby blue, and when he looked at you, his gaze was piercing. The two monks spoke to each other in Tibetan for a long while. I could not understand them, but I deduced that their laughter was a sign that they had clearly appreciated my question and provocation.

The second week passed quickly, and the final hours of the course were all spent in summarizing discussions. That last Saturday we were all happy and at the same time sad that our time together was already coming to an end. Then, for a grand finale, I invited Kyehntse Rinpoche to speak. He spoke to the nuns with his strong, calm voice. He seemed more like a wise old man than a nineteen-year-old monk. I do not know, of course, what he said, but it was a relatively long talk, with the nuns listening with the utmost attention.

Then he gave me a long ‘‘thank-you’’ in English and motioned to one of the nuns. To my surprise, she began to recite some lines of a poem, and then about a half-dozen other nuns each recited a few more lines of the poem. I understood that it was addressed to me, that it represented an opening of familiarity and friendship which, as I was told later, had not been completely approved by the strict director, Khenpo. I read the poem back at the hotel, and found myself quite moved.

Poem of the nuns, the last day

You have travelled from far, all the way from Rome,
To teach us about the big bang, evolution and chromosome.
Throughout our windows new light has come,
bringing new questions, like who is dolly’s mum?
You even told us we evolved from bacteria,
reducing our ego and bringing much hysteria.
You even aroused the curiosity of our Rinpoche,
For your theories, he was left wondering of what to say.
And then there is the question of life and mind,
And if consciousness exists beyond mankind.
And as these debates will continue into the night,
We wish you to return and continue the fight!

[1] P.L. Luisi, 2013, The origin of life at a Buddhist monastery, Rendiconti Accademia dei Lincei, October 2013
P.L. Luisi, The Emergence of Life, Second edit., Cambridge Univ. Press, 2016
H. Maturana and F. Varela, The Tree of knowledge, Shambala, revised edition 1998
F. Capra and P.L. Luisi, The systems view of life, Cambridge Univ. Press, 2014, italian edition Vita e natura. Una visione sistemica Aboca Museum

Read also the First week.