Dear Dr. Weiss, 

Hello. Nice to meet you. My name is Jo Nagai. I’m from Kobe, Japan. I’m in the second grade at Ibuki Elementary School. When I found your research on the internet, I was so delighted!! Two exclamation points. 

When Dr. Weiss opened that envelope in the Georgetown University mailroom, she was stunned. Inside were pages of careful handwriting, photographs of Jo himself—a cute kid with glasses looking through a magnifying glass—and two full pages of data figures.

Dr. Weiss is Dr. Martha Weiss is a world renowned entomologist. She studies insects and she gets fan mail from strangers pretty often. 

Her groundbreaking study discovered that adult moths remember things they learned as caterpillars … even after metamorphosis, the memory carried through to adulthood. 

Her discovery was revolutionary. 

Dr. Weiss said: A caterpillar can have an experience, then go into its chrysalis, five weeks can pass, and it emerges as a seemingly different organism and it still can recall experiences that happened to it as a caterpillar. 

Many a science reporter said: That’s freaking cool!

Dr. Weiss is basically a superhero to anyone into insects, especially butterflies. And Jo, our second grader in Japan, is really really into butterflies.

In Kindergarten, Jo investigated how long a swallow tailed butterfly can stay alive if it got stuck in the chrysalis. In 1st Grade, he’d discovered caterpillars that molt more often than usual.  And now he was hoping to try something more complicated.

He wrote to Dr. Weiss: I’d always thought that my butterflies remember me after metamorphosis because they always flutter around me when I try to let them go into nature. But sadly some say that is ridiculous and impossible.

When Dr. Weiss read Jo’s letter, she realized this wasn’t fan mail. This was a colleague introducing himself. Jo, an 8 year old in Japan, was a full on insect scientist himself. 

This was the most fun letter Dr. Weiss had ever received. 

Jo had no idea what a perfect correspondent he had found in Dr Weiss. The only people she loves talking to more than other entomologists are little kids.

Dr. Weiss wastes zero time writing back to Jo in Japan.

Dear Jo,

I loved reading about your experiments and discoveries and I’m so happy to have a new friend in Japan who loves caterpillars and butterflies as much as I do.

She suggested some simple experiments Jo could do in 3rd grade about training butterflies to remember colors.

To be clear, Dr Weiss didn’t really think Jo could recreate her experiment on moth

memory.  She had a research assistant and an elaborate lab set up. 

They had trained caterpillars to remember by releasing a toxic chemical smell and then giving the caterpillar an electric shock. The smell was associated with pain so the caterpillars moved away from it. 

Once the caterpillars morphed into moths, they tested their reaction to the smell and it was the same. They still hated it. Hence, their conclusion that moths retain memories from their caterpillar stage. 

Toxic chemicals and electric shocks – not really a kid level project.

A few weeks later Jo’s letter arrives.

Jo politely rejects her suggestion for the simple color experiment. 

He writes: I really want to prove it is possible that my butterflies can remember what they learned as a caterpillar. I don’t want to give up now. 

So Jo conducts his own experiment… at home, over summer vacation. 

He uses lavender oil instead of the toxic chemical and uses a little massage gun instead of the electric shock. He trains caterpillars to hate the smell of lavender oil. And then he waits and tests how they react to the lavender smell once they become butterflies.

80 percent of butterflies avoided the lavender smell.

Jo was the first person in the world to discover that memory persists through metamorphosis in butterflies. He sends 4 pages of data in Japanese to Dr. Weiss with a kindly translated summary. There is no doubt memory persists in butterflies through metamorphosis. 

When she reads his letter, her mouth is wide open in amazement, she’s laughing to herself and finally blurts out, “Holy cow!  Jo is a real scientist. He’s discovering new stuff.

Dr. Weiss and Jo correspond for two years across the Pacific.

Her whole family becomes obsessed with Jo Nagai. 

Her husband says, “You don’t expect to hear that level of sophistication in anyone without a PhD. Definitely not someone in elementary school.”

When her adult kids call to check in, they always ask, “What’s the latest update on Jo Nagai?”

In September 2022 Jo presented his research at two universities. And he also graduated from 2nd grade.

In Spring of 2023,  he writes to Dr. Weiss with a whole new research question. 

Jo says: 

By the way, this summer, I’d like to study if memories can be inherited to the next generation. 

Can caterpillar children remember things that happened to their parents?

Memory is happening nematodes … couldn’t it happen in butterflies?

Now Dr. Weiss is truly aghast. She recalls, 

“It had never occurred to me to even ask that question. Jo’s first study was advanced but this was a whole other realm.”

She quickly Googled the nematode study because she was embarrassed to ask Jo to fill her in. 

Jo had intuitively tapped into the scientific field of epigenetics in which scientists study how external factors in the environment can influence how cells behave even while the underlying DNA stays the same. (That’s about as sciency as I can get – someone out there please correct me if I’m saying this wrong!)

Jo was opening the door to generational memory in butterflies – a completely new frontier in biology.

New to science, but not at all new to Judaism. Even before the Holocaust and the relatively new revelations about generational trauma, Judaism, our tradition, the reason we’re all here today, is based on the interconnectedness of generations. 

How many of you are here because you went to the holidays with your parents or grandparents? How many of you are here today because you want your children to have this memory of going to synagogue on the High Holy Days?

We want to imprint this experience on our children so they will carry it on in their families. 

The spiritual connection between generations, the inheritance of memories – both the good memories and the painful ones – is innate to us as Jews. In fact, I could make the argument that all of Judaism – every holiday, every prayer, every meal, every mitzvah – is an expression of generational memory. 

When someone asks us why we’re Jewish we could simply say because of our memories. 

So guess what Jo discovered? 

When he tested a second generation of butterflies, the children of those who had been trained to avoid the lavender smell … Jo wrote to Dr. Weiss …

The results were clear. Butterflies had passed their memories on to their children.  

These holy days prompt us to ask the same question Jo was asking about butterflies … what gets passed from one generation to the next?

What memories do we want to carry with us and what do we need to leave behind?

And more importantly, how do we gently nudge ourselves in the direction we want to grow.

So much of our energy this past year has been in the category I’d call OUTRAGE. 

How can this be the world we live in? How can people do such things? What is happening? How long will this craziness persist? Where are the true leaders? 

Where is the decency? What happened to the middle ground?

The particular ingredients of our outrage are, of course, different – but it seems fair to say we are uniformly outraged. And yet … here we are. 

Are we going to spend our precious days huffing and puffing about the insanity of it all?

What does Judaism have to offer us for a time such as this?

I could make this a sermon about resilience or hope or finding the light in the darkness. I’ve given those sermons often. I’m happy to share my archives if you’re in need of that sermon.

But to me, what this moment needs is something very different.

What we need is to argue, to disagree, to debate.

We need to hash it out … to stop simmering and start serious sparring. 

What Judaism has to offer us at this time is a concept called: Makhlohet Lsheim Shamayim, which means, a disagreement for heaven’s sake. Or let’s edit this to: Makhlohet Lsheim B’nai Adam,  a disagreement for humanity’s sake.

Some of what has happened in the last year is that we’ve lost the big picture. We get so attached to being right, to our narrative, to our facts that we forget that what we actually want to achieve is a better world. 

Me being right or you being right doesn’t create a better world.

What creates a better world is you and me figuring out how to respect each other and not kill each other because of our differences. We need to learn how to disagree for humanity’s sake.

Today we begin that process with a rigorous accounting of our own behavior, specifically how we argue.  

Think back over the last year … what is our personal approach to disagreement? 

Do we avoid? Do we agree to disagree? Do we push our views until the conversation implodes? 

The Baal Shem Tov teaches: “If you see someone doing something that seems wrong to you, examine yourself first. Often, what we criticize in others is what we most need to repair in ourselves.”

He teaches there are three levels of constructive disagreement:

1. Surface Level: “I disagree with you, but I’ll listen politely”
2. Deeper Level: “I disagree with you, but I want to understand why you think that way”
3. Teshuvah Level: “I disagree with you, but I’m open to the possibility that you might be seeing something I’m missing.

Just as we have a love language, we each surely have a “conflict language” and figuring out what that is, and getting more adept at the teshuvah level – maybe I’m missing something – opens the door to a whole new world. 

The famous psychotherapist Ester Perel counsels her couples to identify what they are fighting for rather than what they are fighting about. 

The fight is almost never about who does more work around the house or who has more pressure at work. 

It’s always about one of three things:

recognition – am I respected and recognized for what I’m bringing to the relationship, 

control – do we have equal power in the relationship or is one person making all the decisions, 

and closeness – am I safe, will you really be there for me when things get tough. 

And guess what happens when couples address what they’re fighting for instead of getting stuck on the surface of what they’re fighting about … they get closer. 

By definition they get closer because they understand each other better.

No decent partner would say I want to disrespect you, or disempower you or abandon you. A loving partner asks: how can we work together so we understand each other better and can meet both of our needs.  

This is a makhloket lsheim b’nai adam – an argument for the sake of the human beings involved. 

Judaism expands constructive disagreements beyond our personal lives into communal life. 

Whereas other religions conquered with the sword and changed hearts and minds with dogma, Judaism boldly states: let’s argue our way to a better future. 

How revolutionary! 

How do I know disagreement is the answer to our modern quagmire? 

I know it because our tradition teaches us. 

#1) Judaism teaches that Disagreement reveals our Divine Partnership

Most cultures throughout history have viewed disagreement as dangerous, something to be minimized or suppressed for social harmony. Judaism turned this assumption upside down. 

If God wanted a world of uniform thinking, humans would have been created as angels. Instead, we were given different perspectives, experiences, and reasoning abilities. 

Look at every single biblical hero – Abraham, Moses, King David, Jonah every prophet they all argue with God and frankly with their human counterparts as well. Disagreement is built into the narrative. It’s not a fairy tale – it’s humanity. 

We are B’nai Israel – a people who wrestle with God. And yet, wrestling can get pretty messy and uncomfortable and sometimes offensive. 

You may be thinking – is she really promoting more arguing – has she been on the internet recently? Isn’t there enough yelling and pontificating and carrying on? 

Yes my friends, yes there is. And that’s why our Jewish brand of disagreement for the sake of humanity is so important. There are guidelines and boundaries to this kind of argument so that it serves the higher purpose.

Here is one guideline. 

Sometimes our arguments are not that important. Sometimes when we’re debating borders or guns or Mets vs Yankees or voting rights or whatever issue it is … it may seem like the whole world depends on it – that we’re fighting for survival – and perhaps we are. 

But perhaps we’re not. 

Knowing the difference between what is essential and what isn’t … that is what we’re here for today. Arguments for the sake of humanity require deep personal introspection. 

What values guide us? What are our core non negotiables? What are we fighting for really, not what are we fighting about. 

There is a saying amongst nerdy rabbis like me   … not everything is a humra. Humra means stringency. Like changing your toothpaste or dog food for Passover. Or wearing a kippa and a hat. It’s an extra restriction that’s not really legally necessary.  Not everything is a die on the hill issue. 

Let’s spend time over these days identifying what are our humras. What issues mean the most to us. Just that awareness softens the whole approach to disagreements. 

On what issues can we say, You may be right, or I’d like to learn more about why you feel that way … On what issues can we debate without being attached to the outcome?

Judaism teaches that disagreement is evidence of our uniqueness and our holiness. To avoid disagreement or to whitewash our opinions and perspectives is to deny a key element of our humanness. 

We are built to disagree because God created us as human beings. But that disagreement cannot cancel out our humanity. 

We must be discerning in which disagreements are truly worthy. 

And we must bring our teshuva selves rather than our ego selves to the disagreement so that we can improve life for the many and not just ourselves. 

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Want to hear another reason I believe that disagreements for the sake of humanity are the way forward? 

Judaism teaches that disagreement creates sacred history and strengthens our relationships. 

The Talmud itself is Judaism’s greatest experiment in institutionalized disagreement. Across its thousands of pages, rabbis argue with each other—and with rabbis who lived centuries earlier. What’s remarkable is not just that minority opinions are preserved, but that they’re given equal status. 

Open the Talmud and you’ll see Rabbi Akiva’s position alongside Rabbi Ishmael’s, with no resolution for who is right or wrong.

The Talmud is unprecedented: a sacred text that is a long catalogue of disagreements. 

Could you imagine if we compiled a Talmud today? Who would be included and who would be cancelled? 

Which opinions would spark lots of debate and which would sit there quietly on the page?

Think about that just for a moment. What if all the debate and arguing in our society today were collected in a big encyclopedia and saved for posterity. 

But … here’s the catch … to be included the author had to comply with some essential editorial guidelines. 

To be included the argument would have to follow the framework of Makloket l’sheim b’nai adam. The argument would have to serve the purpose of educating and honoring humanity.

The Talmud actually outlines five characteristics of this kind of disagreement. 

They are: Proper intent; Respect for opponents; Intellectual humility; Constructive outcomes and Preserving relationships.

These five guidelines for constructive disagreements should be posted on every social media site and be signed in a waiver by every social media user. Don’t you think?

If we could follow these Jewish guidelines, we would create more honest discourse and we would actually be working for the betterment of society. Isn’t that the point?

BACK IN BERLIN

I want to introduce you to Bobby and Manuel. They grew up together in England. Bobby is Jewish, the son of a stern, not so communicative Holocaust survivor. Bobby grew up to hate everything German. His father would never buy a German car and even checked the specifications of appliances to make sure nothing was manufactured in Germany. 

Ironically, of all the Jewish kids in Bobby’s neighborhood school growing up, he hits it off with Manuel, a German living in England. They become good friends, lifelong friends well into their adult lives. 

After Bobby’s father dies, he goes to England and discovers a suitcase of letters exchanged between his father and his family during the war. His father had never spoken about his experiences. These letters are a treasure trove … but they’re in German. So Bobby rings up his best friend Manuel and they sit down to read the letters together. 

I wish I could show you the scene in this documentary … Bobby’s face when he finally feels some of the trauma of his father … Manuel’s face when he feels some of the collective guilt of being a German. Suffice it to say … it’s a powerful scene. 

The documentary goes on to explore both Bobby and Manuel’s family history. 

In an unexpected twist, Manuel discovers he is related to a German filmmaker, named Veit Harlan. Harlan was an influential movie maker and celebrity during the war. 

Although he was not a member of the Nazi party, he was handpicked by the Third Reich to create one of the most infamous anti-Semitic propaganda movies of all time. The movie becomes a blockbuster all over Europe and is responsible, if indirectly, for spreading the disease of anti-Semitism across the continent.

Veit Harlan was tried for crimes against humanity after the war.

Bobby is in shock. Again I wish I could show you this scene.  As he’s listening to Manuel, he’s hanging his head looking pale and queasy. His best friend’s uncle was a war criminal and contributed to the hatred that killed his father’s entire family?

I don’t have time to tell you all the twists and turns of Bobby and Manuel’s story. But bottom line: they have many tough conversations and disagreements. 

They go to see the infamous movie together. It’s painful to watch – for both of them. You can see Bobby watching Manuel – this is his great uncle’s creation. 

How can he tolerate it? Will he apologize on behalf of his uncle, will he make excuses? Manuel does neither. He simply confirms that the movie, and the anti-semitism it depicts, are revolting. 

Bobby looks at him: This is all connected to you, your family. Don’t you feel anything?

Manuel: It’s not connected to me. It’s a great uncle who died before I was born.

I’m standing here and I feel like his representative. I feel I have to answer for it. You show me this damning movie and then ask me, so what do you say? 

I don’t know – it’s a bit weird.

Bobby: 

You, all Germans, are connected to the crime that was perpetrated here. 

Bobby wants him to express remorse for his uncle’s role. Take ownership of his great uncle’s actions. He says it explicitly.  I want him to feel the pain I’m feeling.

And then Bobby takes them to Veit Harlan’s home. 

He says to Manuel: 

Perhaps this is an opportunity, having now seen the film, for you to say whatever you’d like to say to Veit Harlan. 

You can feel Bobby silently begging Manuel to apologize on behalf of his uncle, and all Germans. Expecting him to repudiate the violence his uncle’s work perpetrated. 

Manuel looks crushed. He says, “No. I have nothing to say. I have no connection to anything here.” 

Bobby pushes: “Do you feel any differently about having the name Harlan now?” 

Manuel: “No, no I don’t.”

Manuel walks away. 

“Where are you going?” Bobby asks. “I was going to give you a hug.” Manuel has his back turned and is walking away down the street.

They leave Germany, they go their separate ways. 

Bobby says, I started to perceive that my oldest friend was now my enemy.

Time passes, there is no contact between them.

And then a letter arrives in Bobby’s mail from Germany.  A memorial stone is being laid at the site of his father’s home on Zimmerstrasse in Berlin. 

He reaches out to Manuel. 

Bobby apologizes – he is deeply remorseful for pushing Manuel into a role as a German, playing a Nazi in the war games in Bobby’s head. 

Bobby realizes his mistake and the pain he caused Manuel. He apologizes profusely.

Bobby and Manuel take a train to Berlin for the ceremony.

Sitting side by side on the train, Bobby says, “Have you learned anything from this journey? Have you changed in any way?”

Manuel answers, “No I’m not changed but I am grateful.”

He tears up. “I have a renewed a bond with you, my oldest friend. In many ways it brought us closer even though we have our differences.  

I feel honored that you asked me – people don’t often ask for help – it’s one of the great privileges of my life. 

Thank you from the bottom of my heart.”

They hug and are reconnected. 

Their journey from London to Berlin and back again was deep and traumatic. Painful on both sides for many reasons. Ultimately they disagree about how Uncle Veit Harlan should be regarded and the collective responsibility of Germans for the crimes against humanity. 

But … this whole journey created a new sacred history, a new Talmud for the lives of Bobby and Manuel and their families. 

At the dedication ceremony next to the stone that will be laid at his father’s childhood home, Bobby says: To my dear friend, Manuel, without whom I would not have been able to begin this voyage.

And to my dad – thank  you for surviving – 

Shehecheyanu, v’kiy’manu, v’higiyanu lazman hazeh.

Bobby and Manuel’s journey teaches us that a disagreement for the sake of humanity – makhloket l’sheim b’nai adam –  can lead to a closer relationship and even create a positive epilogue to a painful history.  

CONCLUSION

Post October 7, this concept of makhloket lsheim b’nai adam, may sound lofty and naive. I know there are real enemies and real hatred. I know we don’t have as many partners for constructive disagreement as we warrant or even as we thought we did.

That is heartbreaking. Truly – there have been moments this year when the disrepair of our world caused me deep despair. I’ve shed many, many tears over the loss of lives, pain and suffering of our family in Israel and the terrifying state of anti-Semitism in our world. 

I will be speaking more about Israel and the state of the world Jewish community over Yom Kippur. But today I really want to focus on our personal lives. What can we do individually to improve our world?

The answer is based in the Jewish model of disagreement for humanity’s sake. 

Judaism isn’t naive about human nature. The tradition clearly distinguishes between arguments driven by ego and those motivated by higher purposes. 

Our task is to know the difference and engage actively in arguments that will make our world safer and stronger and kinder. 

So my friends, what do you think? Am I crazy? Does this sound like an impossible dream? I believe it is not and I also deeply believe that this is our purpose as Jews in this moment. 

Judaism models a society that  argues its way toward wisdom, debates its way toward justice, and disagrees its way toward deeper understanding. 

And we are its representatives.  What a revolution we would bring if we could bring this vision to our troubled world. 

So as we step into this new year, with as much hope and good intention as we can muster, I will be thinking of Jo Nagai and Dr. Weiss who saw each other with open hearts and shared scientific curiosity. 

I will be thinking of the Baal Shem Tov’s teaching about teshuva level disagreement: where I can be open to the possibility that someone knows something that I don’t.

I will be thinking of the Talmud that brilliantly guides us with the five principles of disagreements for the sake of humanity: Proper intent; Respect for opponents; Intellectual humility; Constructive outcomes and Preserving relationships.

And I will be thinking of Bobby and Manuel – whose relationship truly could have imploded given their Holocaust history, and instead, through their disagreement, grew closer.

These are the bright lights I am taking with me into 5786. I hope you will take these and your own bright lights with me. 

What a gift it would be if we could truly spread the message and method of constructive disagreement to our modern world. 

I pray, for all our sakes, in our personal lives and in our broader community, we can take steps in this direction in this new year. 

L’Shanah tova tikateivu vteihateimu – may we be inscribed and sealed for a good new year. Amen.