All posts by yni957

A letter to Henry Ford

As part of her social study homework, my daughter, Jolene,  wrote a letter to Henry Ford, imagining it from the perspective of Greta Thunberg.  I like the letter but thought it did not sound much like Greta.  Then it occurred to me that I could ask ChatGPT to rewrite it in Greta Thunberg’s style .    Intrigued by the idea, Jolene enthusiastically consented to this experiment. She has also given her permission for both the original letter and ChatGPT’s adaptation to be shared here.  I hope you have as much fun as I had reading these!


Jolene’s original letter

Herr Henry Ford,

Isn’t it interesting how one day can change your life, and you wouldn’t know? I remember that day like it was yesterday. I remember sitting down at my desk at school, not knowing that my story was just about to start. The teacher announced that we would be watching a film about the state of our environment. I remember how as it progressed, my feelings grew from curiosity to horror as pictures of endless mountains of garbage floating in the ocean flitted across the screen. I will be the first to admit it: I cried. I remember every vivid detail, though my classmates all forgot the atrocities they just witnessed mere minutes after the film ended, apparently deciding that discussing their weekend plans was more important than the outrageous amounts of garbage and smoke that pollute our planet. It’s a strange feeling, looking back and knowing that this film would be forever engraved in my mind. I’m sure you would feel the same about the assembly line, looking back at when you invented it, when you didn’t know you would revolutionize the automobile forever. I suppose that means I shouldn’t blame you for the polluting smog cars let out into the environment every day. Yet, as I sit here in my room, sun warming the paper I write on, I can hear the cars passing my home, and I can picture the cloud of smoke that lingers behind. Too much has been done to our Earth for me not to take a stand.

I understand that when you were innovating and popularizing the automobile, your intentions must have been good: to make people’s lives easier and better. If that was your goal, then you achieved it. At least, at the time you achieved it. On the surface level, it seemed perfect: more jobs were created that more workers were qualified to do, which made our country’s economy stronger. Cities became less crowded as people moved to neighboring towns to form suburbs since they could drive to work. It bridged a gap between different classes of people as it became a norm that men and women, rich and poor alike drove together on the roads. But at what cost?

In 2024, the global temperature has increased by about 1ºC since 1900, with the majority happening after 1970. As a result, the ocean has warmed as well, causing ice caps to melt and the sea level to rise. A main cause of this is the burning of greenhouse gasses. Only approximately 8% of Americans do not own a car. A glance out the window during a busy time of day will show streets packed with everything from fancy red convertibles to rusty pickup trucks. I have worked to decrease the damage our race causes to the Earth, yet it still rises. People are all for helping to stop climate change until it actually inconveniences them. Few are willing to give up constantly driving their car instead of walking, biking, or using public transportation, or to fly across the world a few less times. While in my mind I realize that not all of this is your fault, my heart protests against it, aching for the state of our world. Neither of us can help it if your life’s work happens to clash against mine.

All of this goes to say that, while I respect how hard you worked to make the automobile what it is today, I will work twice as hard to ensure that the damage is undone. I will not apologize for that.

Greta Thunberg


ChatGPT’s Version

Dear Mr. Henry Ford,

The day everything changed for me was just another day at school, until it wasn’t. We watched a film about our planet’s environmental crisis, and the images of pollution and destruction struck me to the core. It was a moment of awakening — a stark, horrifying realization that we are in the midst of a grave crisis. I remember the despair I felt, a sharp contrast to the indifference of my peers. Such moments define us, much like the day you pioneered the assembly line must have defined you, unknowingly setting off a chain of events that would lead us here.

Your innovation brought mobility and progress, but at a catastrophic environmental cost. We now face a planet warmed by over 1°C since 1900, mainly due to emissions post-1970. The burning of fossil fuels, a legacy of the automotive boom you ignited, has pushed our planet to the brink. Our ice caps are melting, our seas are rising, and our future is at stake.

I understand that the environmental crisis we face today cannot be solely laid at your feet. However, the industry you created has played a pivotal role in this unfolding tragedy. As I witness the relentless march of cars outside my window, each contributing to a cloud of pollution, I am reminded of the urgency of our situation.

Mr. Ford, while your intentions may have been to better the human condition, the reality is that we are now paying a heavy price for this ‘progress.’ I respect your ingenuity, but I cannot overlook the environmental devastation it has wrought. I am committed, more than ever, to fight for a sustainable future, to challenge the status quo, and to reverse the damage we have done to our Earth. This is not just a promise; it is an imperative.

We are at a crossroads, and I will not rest until we choose the path of sustainability, responsibility, and survival. I will advocate, protest, and work harder than ever to ensure a future where technology serves our planet, not destroys it. This is the mission of my generation, and I accept it wholeheartedly.

Yours in determination,
Greta Thunberg

Open-TNM

Finally, this little C++ project that I started more than 20 years ago went open source at Github, mainly thanks to the diligence and passion of Prof. Jun Xie, a former student and now collaborator at Southwest Jiaotong University.  As of now, it contains just one traffic assignment algorithm (the greedy algorithm we developed a few years back), but the plan is to gradually release many more in the coming months.

I began to develop TNM –which stands for Toolkit for Network Modeling– in 2003.  The project is a collection of C++ code I wrote to deal with many different transportation network problems, ranging from origin-destination estimation to microscopic traffic simulation (yes, I had even written a microscopic simulator based on Cellular Automata.   It seems like an extravagant waste of time, with the benefits of hindsight).   In March 2006, when I was wrapping up my PhD research at UC Davis, I wrote a document summarizing the development up to that point, which I have since frequently quoted in my papers that use the code to produce numerical results.  You may check it here.

My development of TNM would continue well into my tenure at Northwestern.  In fact, as late as in 2015, I was still busy putting stuff into TNM.  Over the years I developed a rather flexible and universal GUI based on MFC  that has the ability to accommodate many different types of network problems — at one point I even learned to deal with GIS  functions in my GUI.  I would be lying if I tell you I did not enjoy the thrill of making a machine do what I command….  However, eventually, I realize that I must stop indulging in this hobby as it has become a black-hole swallowing an undue amount of my energy that was in short supply given my increasing seniority and the  responsibilities  that came with it  (I am sure this epiphany came to me a bit too late).

Right around the time I decided it is the time to pass the torch to the next generation, Jun showed up in my lab, first as a visiting PhD student then as a visiting postdoc.   Unlike the vast majority of my other students, he did not mind wresting with the messy C++ code I wrote in  haste.  On the contrary, he seemed to truly enjoyed it.  So, Jun gradually became involved in the development of TNM  and, after  joining Southwest Jiaotong University, has added to the development team his own graduate students.  Without Jun, the publication of TNM on github probably would never have happened.

 

Crusaders

Dan Jones is a great chronicler.  He knows how to turn dry events into vivid stories, which characters to focus on so his narrative always has a humanly anchor point, and when to make witty quips without being seen as overly opinionated.   Some writers have the talent to captivate their audience with no more than the charm of their language – I think Jones is one of them.

“Crusaders” covers nearly four centuries of medieval history, from the end of the eleventh century CE, when Pope Urban began to preach the Holy War against the infidels in the east, to the conquest of Jerusalem by the Ottman empire in 1517.   Officially, crusading met its calamitous end in 1291, when Acre, the last stronghold of the Christian kingdoms in the east, fell to the hands of Mamluks.   However, as a phenomenon, crusading continued until Columbus’s discovery of America––which was “full of things to trade or steal, and teeming with people to subjugate, convert or kill”—convinced Western Christendom that its future “lay to the west, not the east”.

Out from this eventful and bloody chapter of human history stand a few prominent and complicated characters that I think deserve some ink even in a brief book review.

Richard the Lionheart, the legendary king of England who spent most of his adult life in France, was the commander in chief in the Third Crusade.   Rumored to be a gay, Richard was famed for his martial prowess, courage and generosity. He also was a man of letters who loved lyric poetry and music and courted poets of High Middle Ages.  Under Richard’s leadership, crusaders retook Acre and delivered a string of humiliating blows to the army of the mighty sultan Saladin of Ayyubid Dynasty, but ultimately fell short of seizing Jerusalem itself.  The struggle ended with a negotiated truce that placed the coastal towns between Jaffa and Acre under the Christian rule, while allowing Christian pilgrims and merchants to access the Holy City.  Although the settlement helped stabilize the Kingdom of Jerusalem for decades to come, it forever transformed crusading from a religious imperative into an enterprise of colonization.

Like many powerful men of his age, Richard was often reprimanded in history books for being lustful, greedy, and cruel.  I suspect some of Richard’s vices were exaggerated by the clergymen who resented him for being forced to pay for his military adventures.  That said, the extent of Richard’s cruelty is indisputable.  The most notorious episode was the execution of 2600 unarmed and bound prisoners of war at Acre, as a retaliation against Saladin’s failure to fulfill his promise to “return the relic of the True Cross and pay his bounty”.   Be technically legal as it may, noted Jones, this despicable act of cruelty was “excessive even by the standards of the day”.  Little wonder Richard’s name has acquired such an infamy in the Muslim world that it was often invoked by impatient moms to calm their unruly children.

Enrico Dandolo, the doge of Venice, was the hero––or the villain, depending on who you ask––in the Fourth Crusade.  He took the cross at an incredibly advanced age of 95, having gambled his country on a military alliance according to which Venice would equip and supply the Fourth Crusade in exchange for 85,000 silver marks.  When Dandolo realized his airheaded partners could not pay their dues, he decided to save Venice from bankruptcy by what essentially amounted to organized robbery.   His first target was the city of Zara, a possession of King Emeric of Hungary who was not only a pious Chrisitan but also a fellow crusader.  Zara’s sacking infuriated Pope Innocent III as he had explicitly forbidden it.  As a result, all Venetian crusaders were “excommunicated”, i.e., officially expelled from the Catholic Church.  Dandolo couldn’t care less. He soon seized another opportunity that promised even more money, by injecting the crusaders into a conspiracy aimed at dethroning the Byzantine emperor.  There is no space to recall the entire drama – suffice to say that it led to the siege and fall of Constantinople in 1204.  Once again, Dandolo’s allies failed to hold their side of the bargain, so it seemed as if he almost had no choice but to help himself with what was promised to him.  For three days, the crusaders vandalized the richest city in the West.  The estimated total value of the loot amassed during their plundering is believed to be around 900,000 silver marks.  If this figure is accurate, then Venice’s investment in the Fourth Crusade yielded a staggering tenfold return.   Dandolo thus exemplified the notion of prospering by doing God’s bidding – a modern entrepreneur from Silicon Valley would recognize this as the medieval version of “doing well by doing good”.

At the time, many ancient and medieval Roman and Greek works were stolen and sent back to Venice. The most notable were the four bronze horse statues from the Hippodrome, believed to have been crafted in the second or third century CE.    When I visited Venice in the summer of 2023, a replica of these magnificent statues was indeed, as Jones teased, “still proudly displayed at Saint Mark’s Basilica.”  Our Venetian tour guide was careful not to dishonor what is considered a national treasure in her country. The horses, she told us, were “brought back” from Constantinople 800 years ago.

Dandolo died a year after the fall of Constantinople. He was 98 and had been visually impaired for more than three decades.  The crusaders understandably cheered what they had accomplished under the command of the aged and fragile man as a miracle.  To many a Christian, however, the brutal sacking of Constantinople was a dark and scandalous chapter in the history of their faith.   The cruel irony—a mission sanctioned by the Catholic papacy resulting in the destruction of the spiritual capital of the Eastern Orthodoxy—was simply beyond the pale.  Jones summarizes Dandolo’s controversial involvement in the crusade aptly:

“He had bravely defied his physical disability and his decrepitude, and his pragmatic leadership and dauntless personal valor were beyond question. Yet in the end Dandolo had turned his talents to a wholly disreputable end, playing a leading part in a dreadful episode that, even by the cruel standards of the crusading era, thoroughly deserved the epithet leveled against it by Choniatēs: “Outrageous.”

Another fascinating historical figure from this era is the leader of the Sixth Crusade, Frederick II, the emperor of the Holy Roman Empire.   His famed grandfather, Frederick I “Barbarossa”, drowned while attempting to cross a river during the Third Crusade.  About 750 years later, Adolf Hitler, in a seemingly ironic twist, named his ill-fated Russian campaign after the elder Frederick.  However, Frederick II succeeded where his progenitor faltered. Through an agreement reached with the Ayyubid sultan Al-Kamil, he regained control of Jerusalem in 1229, a feat that three costly crusades had failed to accomplish in four decades.  To be sure, Frederick II enjoyed good fortune, as Ayyubids were distracted by potential conflicts with its Muslim brethren in Syrian and Mesopotamia. However, there is no question that the emperor’s intelligence, personality, pollical acumen and breadth of knowledge also played a crucial role. Fredreick II was, in the words of Jones, “a shockingly liberal intellectual and a bluntly pragmatic ruler”.    He spoke six languages, including Arabic and Greek, boasting a reputation as a polymath.

Fredreick was a man with an insatiable curiosity about the natural world that extended far beyond the tenets of Christian Scripture. He loved natural sciences, astrology, logic, rhetoric, medicine, law, philosophy and mathematics…(and) surrounded himself with Latin, Greek, Muslim and Jewish tutors, advisers, poets, scholars and bureaucrats. Well into adulthood, he retained a personal Arab tutor in logic, and he corresponded with Jewish and Arab scholars in southern Spain.

In short, Frederick was a philosopher king in the Platonic ideal, reminiscent of figures like Marcus Aurelius of the Roman Empire and Kangxi of the Qing Dynasty in China.

Paradoxically, the “greatest and least bloody crusading victory” won by Fredreick was met with universal condemnation rather than exaltation among his fellow crusaders.  When the emperor left Acre, it was reported, he was “hated, cursed, and vilified”. Why? Ostensibly, the reason was that his participation in the Six Crusade was technically illegal because he had been excommunicated by the pope for allegedly failing to honor his previous crusading pledge.  However, his quarrels with the papacy ran deep and deteriorated following his triumph in the east.  Eventually the most successful crusader of his time would become himself the target of a crusade officially endorsed by the Catholic church.  Although Fredreick “could be infuriating, overbearing and self-serving”, concluded Jones, it is still difficult to “conceive of a greater perversion of the institutions and language of crusade than for such a war to be preached against” him.

Beneath the veneer of glory surrounding these crusading kings and generals lay unspeakable violence, horrific human suffering, and ferocious atrocities.  After all, as Jones noted, “there was precious little time for thoughts of human rights on either side” of the crusading divide.

When Baldwin II of Kingdom of Jerusalem laid siege to Aleppo in 1124––toward the end of his futile effort to break into the Syria interior—his army reportedly engaged in “elaborate rituals of depravity” against the Muslim residents.  According to Jones, the crusaders

“raided Muslim funeral chapels, took coffins to repurpose as storage chests for their camp, then goaded the citizens with the sight of their dead relatives’ corpses being grotesquely desecrated…Whenever the Franks captured an Aleppan Muslim, they cut off his hands and testicles.”

During the Fifth Crusade, Damietta, the third-largest city in Egypt, endured a siege lasting a year and a half.  Even the battle-hardened crusaders were apparently horrified by what they saw in the once-thriving city. It had transformed into a ‘fetid, disease-ridden graveyard, inhabited by mere skeletons and ghosts.’ The few survivors were overwhelmed, unable to bury the countless corpses that littered the streets, and the stench “was too much for most people to bear”.   Shocked as they might be, the crusaders showed little pity, much less remorse. Soon enough, wrote Jones, “Christian thieves” began to “run around taking what they could” and force starving Muslim children to undergo baptism.

When Jerusalem fell to the raid of a Khwarizmian (花刺子模) mercenary army of Ayyubid sultan in 1244—only 15 years after Fredrick’s diplomatic victory—it was utterly devastated. The Khwarizmians hunted down and slaughtered six thousand Christian civilians trying to flee the abandoned city. Then, on August 23,

the Khwarizmians entered the almost empty city of the Israelites and in front of the Sepulchre of the Lord they disemboweled all the remaining Christians who had sought refuge inside its church. … The marble around Christ’s tomb was either smashed or scavenged and the tombs of all the crusader kings of Jerusalem buried near Calvary were opened and their bones tossed away. Elsewhere other highly revered Christian churches and shrines received the same treatment: the priory at Mount Sion, the tomb of the Virgin Mary in the valley of Jehosophat and the Church of the Nativity in Bethlehem were all desecrated.

Ironically, the Khwarizmians were themselves victims at the hands of an even more formidable force. About 25 years earlier, the horde of Genghis Khan had besieged and pillaged Samarkand, the capital of their empire.   In some sense, he was indirectly responsible for the terrible losses of Christians in 1244, as the collapse of the Khwarizmians empire had left its jobless soldiers to scatter around, much like a deadly shock wave sweeping through the Middle East.  The Mongols, of course, did not discriminate between Christians and Muslims.  When they captured Baghdad, arguably “the most civilized of cities” at the time, they killed at least 100,000 Muslims.   Yet, their worst crime against humanity was probably destroying the great city’s House of Wisdom, a library that “contained the largest and most sophisticated collection of books on earth” – so many books were thrown into the Tigris, wrote Jones, “that the water was said to have flowed black with ink.”    

No medieval horror movie would be complete without mentioning the hideous crimes against Jews.  In fact, the First Crusade marked a tragic turn in the fortunes for Jewish diaspora in Western and Central Europe.

In 1096, even before leaving their own country for the First Crusade, French and German crusaders turned on local Jewish communities.  At Mainz, they stormed the residency of archbishop Ruthard where seven hundred Jews sheltered for his protection.  The indiscriminatory slaughtering by this mob was so appalling that many desperate Jews killed each other to avoid execution by the “weapons of the uncircumcised”.  Similar mass murders took place elsewhere.  In Cologne, according to Jones, “young men and women threw themselves into the Rhine and fathers killed their children rather than see them fall into the hands of the enemy”.   This “orgy of anti-Semantic violence”, collectively known as Rhineland massacres, is widely seen as a harbinger for what was coming for Jews in Europe in the next millennium.

About a hundred years later, the fervent zeal ignited by the Third Crusade engulfed the English populace. Months of riots against England’s Jews ensued.  During this period, it was not uncommon to witness mobs chasing and assaulting Jews in the streets, forcing them into coerced baptisms.  The worst incident occurred in York in March 1190, when hundreds of Jews, seeking refuge in the city’s castle, were either killed or forced to commit mass suicides.  The persecution of Jews in England would continue and culminate in 1290, when the country officially expelled its Jewish population and enacted a ban that would last nearly four centuries.

Shortly after I finished reading “Crusaders”, on October 7th, 2023, Hamas militants perpetrated the worst mass murdering of Jews since the Holocaust.  There is no need to recite the details of the crimes.  Anthony Blinken, the US Secretary of State, summed it up well: “depravity in the worst imaginable way”.   Viewing this incident in the context of crusade, however, I felt that I have seen the movie before. The latest version is set on the same stage and has a similar plot, though played by different actors.  In this movie, it was Jews, rather than Christians, who were the infidels that Muslims tried to expel from the land they believed was righteously theirs.  

History has never stopped projecting the conflicts in Palestine through the lens of the Crusades.  When British general Edmund Allenby marched into Jerusalem as a victor in 1917, ending the four-hundred-year control of the Holy City by the Ottoman Turks, he proclaimed, allegedly, that “the wars of the crusades are now complete”.   Whether he said it or not, the forecast was wrong. The British mandate of Palestine would give way to the rebirth of the Jewish state in what many Muslims saw as a continuation of the medieval crusades, only this time Jews and Christians were co-conspirators. Surely that was how Osama Bin Laden saw it. In the ‘Letter to the American People’, now widely circulated thanks to Tik-Tok, he wrote,

Palestine has been under occupation for decades, and none of your presidents talked about it until after September 11. … You should be aware that justice is the strongest army and security offers the best livelihood; you lost it by your own making when you supported the Israelis in occupying our land and killing our brothers in Palestine.

Likewise, President George W. Bush once likened the US response to the 9/11 attack to a crusade, warning the American people that “this crusade, this war on terrorism, is going to take a while”.  

Even the rhetoric sounds eerily similar, and it always invokes some version of a just war, i.e., the “violence that was regrettable but legitimate and even moral, so long as it was undertaken to protect the state and would ultimately serve to produce or restore peace.”  Bin Laden put it more bluntly, “it is a sin to kill a person without proper, justifiable cause, but terminating his killer is a right.”  What remains unsaid and perhaps unknowable, however, is who gets to decide what causes are proper and justifiable, and how far back in history one must trace them.

Hence, the life-and-death struggle for the Holy Land, waged in the name of that One True Faith, has never really ended. And the idea of crusading will perpetuate cycles of violence and plight as long as there are crusaders on Earth.

 

Marco Nie, Northwestern University

December 30, 2023

 

 

Entropy maximization for multi-class assignment

The lack of uniqueness constitutes a serious concern for any analysis that relies on class-specific traffic assignment results, such as understanding the impact of a transport policy on the welfare of travelers from different income groups, sometimes known the vertical equity analysis.  Entropy maximization is a standard approach to consistently selecting a unique class-specific solution for multi-class traffic assignment.

Here, we show the conventional maximum entropy formulation fails to strictly observe the multi-class bi-criteria user equilibrium condition, because a class-specific solution matching the total equilibrium link flow may violate the equilibrium condition. We propose to fix the problem by requiring the class-specific solution, in addition to matching the total equilibrium link flow, also match the objective function value at the equilibrium.  This leads to a new formulation that is solved using an exact algorithm based on dualizing the hard, equilibrium-related constraints.

Our numerical experiments highlight the superior stability of the maximum entropy solution, in that it is affected by a perturbation in inputs much less than an untreated benchmark multi-class assignment solution.  In addition to instability, the benchmark solution also exhibits varying degrees of arbitrariness, potentially rendering it unsuitable for assessing distributional effects across different groups, a capability crucial in applications concerning vertical equity and environmental justice. The proposed formulation and algorithm offer a practical remedy for these shortcomings.

This is the third paper completed by the first author, Qianni Wang, who officially joined my group last year.

The paper was currently under review at Transportation Research Part B.  You may download a preprint here, or read the abstract below.


Abstract: Entropy maximization is a standard approach to consistently selecting a unique class-specific solution for multi-class traffic assignment. Here, we show the conventional maximum entropy formulation fails to strictly observe the multi-class bi-criteria user equilibrium condition, because a class-specific solution matching the total equilibrium link flow may violate the equilibrium condition. We propose to fix the problem by requiring the class-specific solution, in addition to matching the total equilibrium link flow, also match the objective function value at the equilibrium. This leads to a new formulation that is solved using an exact algorithm based on dualizing the hard, equilibrium-related constraints. Our numerical experiments highlight the superior stability of the maximum entropy solution, in that it is affected by a perturbation in inputs much less than an untreated benchmark multi-class assignment solution. In addition to instability, the benchmark solution also exhibits varying degrees of arbitrariness, potentially rendering it unsuitable for assessing distributional effects across different groups, a capability crucial in applications concerning vertical equity and environmental justice. The proposed formulation and algorithm offer a practical remedy for these shortcomings.

汪精卫其人其诗

汪精卫其人其诗

从小到大,不论在哪里看到汪精卫这三个字,我都会条件反射似地脑补出“遗臭万年”,“身败名裂”, “卖国求荣”这些字眼儿。除了大汉奸的名头,我还听说汪是坊间传闻的民国四大美男子之一,娶了个很彪悍且同是大汉奸的老婆叫陈璧君。然后呢? 就没有然后了。没有记错的话,中学历史教科书中对他着笔甚少,少到连做汉奸的来龙去脉都语焉不详,仿佛这件事虽然惊世骇俗、可耻可恨,但左不过是跳梁小丑螳臂挡车的一幕闹剧,不值得祖国的花朵们劳神分心。至于他的人生,一个叛国投敌、罪行昭彰的独夫民贼,人生的故事就算再跌宕传奇,还值得花时间去了解吗?

第一次开始对汪精卫感兴趣是发现他写过一首流传甚广的《被逮口占》:

慷慨歌燕市,从容作楚囚。

引刀成一快,不负少年头。

我最开始无法相信一个大奸大恶之人能写出这样视死如归、回肠荡气的绝笔诗,甚至怀疑过是别人捉刀之作,情状颇似《围城》中方鸿渐写给苏小姐的道歉信里所言,“见名章隽句,竟出诸伧夫俗吏之手,惊极而恨,遂厚诬以必有蓝本。” 惊愕归惊愕,对先入为主的人来说,这首诗跟汪精卫的不和谐之处其实也不难解释。或者他当时年轻气盛,一时冲动谋刺满清王公,失手被捕自知不免,乃故作激昂语,后侥幸得脱,心性大变,加上权力场中几度沉浮,终于蜕变成贪生怕死,利欲熏心的无耻之徒,也是有的。

再后来,某日在微信群里偶然聊起中日战争,有位群友推荐了汪兆铭的《双照楼诗词稿》 (有余英时、叶嘉莹两位先生作序的2012版,以下简称《双照楼》)。很惭愧,我当时还不知道汪兆铭即汪精卫—精卫是他早年追随孙中山闹革命时,写文章用的笔名。中国旧体诗是我唯一勉强能读懂的诗,但对于看诗集,我无论兴趣还是学养都不够。幼时随祖父启蒙读过些唐宋诗、魏晋文,很喜欢,但那都是精选的历代大家扛鼎之作,言浅意深,脍炙人口。从头到尾通读某位诗人的集子,我从来没想过尝试。最后决定《双照楼》值得一读有两件原因。

第一件是余、叶二位的序。余英时的长序,虽自言不是为汪翻案,但是言语间对汪人品才具的评价极高。至于对汪“投敌卖国”的分析,二位先生似乎都认同胡适的观点。胡适说汪“一生吃亏在他以‘烈士’出身,故终身不免有‘烈士‘的complex『复杂』。” 叶嘉莹在她的短序里说汪有“终身不得解脱的一种‘精卫’情结”。 余先生则加上了“汪精卫在本质上应该是一位诗人”的判断,当然更要命的仍是,“这位诗人一开始便走上’烈士‘的道路,因而终生陷进了权力的世界。这样一来,他个人的悲剧便注定了。”

第二件,便是那位群友顺手拈来,出自《双照楼》中的一首七绝《送别》:

把酒长亭杯已空,行人车马各西东。

枫林不共斜阳去,自向荒郊寂寞红。

中国旧诗有种叫“意境”的神奇力量,可以倏然而至,如子弹般击中你,让你感受到发自灵魂深处的震撼,但却无法言喻。不知为何,这首诗给我的冲击,比《被逮口占》还要强。王国维说,“有境界则自成高格,自有名句”。《送别》营造的“境”—远去的友人,空灵的酒杯,寂寞枫林,独立斜阳—与一种卓尔不群、孤标傲世的“格”水乳交融,浑然天成,造诣之高,已堪与盛唐名篇比肩。也许是做科研落下的职业病,我向来对有争议的人物和话题充满好奇。有什么比一个千夫所指但才华横溢的诗人兼政客更有争议性呢?我下决心要把《双照楼》从头读一遍,试试能不能从中发现一个真实的汪精卫。

《双照楼》里收集诗词的数量我没作统计,但应在数百之间。以我对旧诗的陋见,写不出值得一读的评论。个人最大的体会是汪诗的自然真诚,以及倾注其中的强烈情感。如果说“言志”是写诗的终极目标和最高境界,那这一点我觉得他近乎完美地达到了。钱钟书认为汪是做秀,规劝他“莫将愁苦求诗好”(注一),学生实不敢苟同。钱老当年也许童心偶发,闲笔戏题。但正如余英时所说,他不仅所见不明,且大失公允。叶嘉莹称汪精卫是“用生命来写作自己之诗篇“的”真正的诗人;为《双照楼》写后记的汪梦川赞汪诗“雅正纯粹、绝无俗态”,均为持正之论,于我心有戚戚焉。汪精卫的诗到底告诉我们,他是一个怎样的人呢?

首先,汪精卫绝非贪生怕死之辈。

汪被捕后坚称自己为主谋,决意要为同案之人开脱(注二)。他在狱中羁押了快两年,写了不少诗,其中不乏大义凛然的篇章。《被逮口占》共有四首五绝,除了人们耳熟能详的第三首,第四首也极好:

留得心魂在,残躯付劫灰。

青燐光不灭,夜夜照燕台。

“残躯付劫灰”本来是诗人的愿景,但他大概没想到在自己身后,中国人民倒是帮他一字不漏地兑现了(注三)。另外印象深刻的一首是悼念挚友胡汉民的五律(注四)

马革平生志,君今幸已酬。

却怜二人血,不作一时流。

忽忽余生恨,茫茫死后忧。

难禁十年事,潮上寸心头。

艳羡战友马革裹尸的夙愿业已达成,而自己却不能随他同赴国难,悲叹余生无涯,捱不尽的后死之忧(也算一语成谶)。字字是血,动人心魄。中国文人绝笔诗历史上不少。最出名的当数南宋文天祥的“人生自古谁无死,留取丹青照汗青”,写尽了为国捐躯的民族英雄们最常见的一种心理。类似风格的我知道还有南明张煌言的“惭将赤手分三席,敢为丹心借一枝”(注五)。但以青史留名、与先贤比肩来为精忠报国、死而后已的大义背书,以“格”而论,似乎既没有“引刀成一快”洒脱,也不如“留得心魂在,夜夜照燕台”纯粹。当然,谭嗣同“我自横刀向天笑,去留肝胆两昆仑”,不仅笑对死亡,还看到了另一种选择同样高尚的可能,在境界上似乎又更上一层楼。汪精卫出狱之后,心理上已经死过一次,不知道后来是不是也悟到了这层境界,堪破生死玄关,以至于三十年后决心要试试另一条路究竟有多难走。

其次,汪精卫热爱生活,也善待别人。

汪写羁旅行役、游玩题赠的小诗,别开生面,充满生活情趣。比如这首他的得意之作,

初阳如月逗轻寒,咫尺林原成远看。

记得江南烟雨里,小姑鬟影落春澜。

在给胡适的信中专门提到,确是佳构。1926年春节游白云山记下在农家所见,道作

村儿绿袴女红妆,分得黄柑著意尝。

却道城中风物好,不知身在白云乡。

朴实真切,回味悠长。二十年代在法国写的《游日内瓦湖》,颔联作“暂留残照天边树,尽抹微云雨后山”;另一首《夜泛》中间四句,“风平波去懒,云碎月行忙。萤火出林大,渔灯在水长”。这类炼字清奇,读来余香满口的句子,在他的集子里,所在多是,不胜枚举。

汪精卫一生大都在路上奔波,光在中国和西洋之间就来回过至少六次 (注六),至于打了败仗亡命东洋、革命要钱去南洋募捐,更是家常便饭。那时候去趟欧洲的旅程要用月来计算,所以他集子里收了大量船上写的诗。比如这首1919年去法国途中写的《舟中晓望》就琅琅上口:

朝霞微紫远天蓝,初日融波色最酣。

正是暮春三月里,莺飞草长忆江南。

1915年从上海去南洋筹划讨袁途中写下的《寄冰如》(冰如是陈璧君的字),则是羁旅行役结合爱人同志的代表作:

一去匆匆太可怜,只余巾影淡于烟。

风帆终是无情物,人自回头舟自前。

汪精卫和陈璧君当年同船南下,陈在香港登陆改乘火车回广州归宁,汪则继续同船前往南洋,这首小诗想来是他看着夫人远去的背影写下的。当时汪精卫32岁,和冰如已育有一子一女,但二人伉俪情深,恩爱溢出纸面。所谓河东狮吼云云,不知是否也是好事之徒捕风捉影。汪夫人在《双照楼》里一直保持很高的出镜率,汪先生除了船上寄冰如,还有飞机上寄冰如,坐在家里想冰如,以及陪冰如四处游玩等等。最好的一首的我觉得是《高阳台 冰如导游西湖》,其词曰

风叶书窗,霜藤绣壁,萧疏近水人家。
初日钩帘,遥青恰映檐牙。
湖山已,似曾相识,况旧游,人倚平沙。
最勾留、泉冷风篁,石醉烟霞。
湖光不被芳堤隔。但东西吹柳,远近浮花。
水澹山柔,轻烟晕出清华。
夷犹一棹凌波去,乱野凫、飞入蒹葭。
夜如何?
皓月当头,照澈天涯。

前面写景华美妩媚,极尽渲染烘托之能事,颇得婉约之风,但收尾的“皓月当头,照澈天涯”八个字画龙点睛,同时营造出身临其境的体验和无穷的想象空间,远非一般名家的婉约词所能望其项背。

汪精卫爱夫人也爱女儿。去世一年前在飞机上写给三女文恂的诗,有“四野春光融作水,千山朝气蔚成霞。 老牛含笑看新犊,雏鸟多情哺倦鸦”四句,舐犊之情,跃然纸上。他也珍惜朋友,《舟夜》中“良友渐随千劫尽“的感慨,《虞美人》里“故人热血不空流”的悲怆,都在向先他而去的战友们致敬。

他四十年代为义妹方君瑛忌辰写的悼亡诗,中间四句是“孤悬破碎山河影,苦照萧条羁旅人。南去北来如梦梦,生离死别太频频”。真情仍在,风骨犹存,但诗中的阳光明媚早已转为孤寒凄苦。钱钟书说他的诗“似觉南风有死声“,描述这个时期的风格大体不差。

其三,汪精卫性格温和,反对滥用暴力。

汪精卫早年思想激进,支持以暴力革命的手段来救亡和唤醒民众。但是,清政府对他的宽大处理和辛亥革命的和平解决似乎让他对暴力的态度发生了变化。他后来在政治生涯中的几次重大关头都选择了怀柔而非暴力。二次革命反对孙中山借宋教仁之死发动战争,1927年反对蒋介石借分共大开杀戒,最后一次当然是抗战最低潮的时候选择放弃抵抗。汪精卫不相信“枪杆子里面出政权”。身边好友曾苦劝他一定要做“军事家”才能成就大事,但他对此毫无兴趣(注七)。

他作于1939年的《金缕曲》,描写战乱之下的国家,山河破碎,遍地新冢,寡妇孤儿,泪眼相对,其词凄婉悲切,读来如闻其声,如见其泪。词曰,

绿遍池塘草。
更连宵、凄其风雨,万红都渺。
寡妇孤儿无穷泪,算有青山知道。
早染出,龙眠画稿。
一片春波流日影,过长桥、又把平堤绕。
看新冢,添多少。
故人落落心相照。
叹而今、生离死别,总寻常了。
马革裹尸仍未返,空向墓门凭吊。
只破碎山河难料。
我亦疮痍今满体,忍须臾、一见欃枪扫。
逢地下,两含笑

汪精卫这类感时伤怀,悲天悯人作品中的巅峰之作,应该是《朝中措—重九登北极阁》(注八)

城楼百尺倚空苍,雁背正低翔。

满地萧萧落叶,黄花留住斜阳。

阑干拍遍,心头块垒,眼底沧桑,

为问青山绿水,能禁几度兴亡?

这首词写于1943年重阳,余英时分析当是汪氏词中绝笔。最后两句套用元好问“故国江山如画,醉来忘却兴亡”。但“能禁几度兴亡”六个大字,道尽古今仁人志士,在我中华兴亡铁律面前,那种深沉的痛惜和无奈,与原词的消极避世相比,高下立现。

最后,汪精卫骨子里是一个孤高自许的士人。作为政治家,他有独立思想,有原则底线,不随波逐流,但作为领袖人物,意志似不够坚定,时常首鼠两端。

汪精卫大概是孙中山最忠实也最信任的追随者,不仅是孙的接班人,甚至连 “革命尚未成功,同志尚需努力” 的总理遗嘱都出自他的手笔。但是汪好几次公开反抗孙的主张。刺杀摄政王载沣一事,他与持反对意见的孙中山、黄兴多次辩论,最后一意孤行,决意赴死。二次革命前他主张依法解决宋教仁遇刺案,甚至亲身前往广州呼吁革命党人放下武器,与袁世凯和谈。护法运动后,孙中山在广州成立军政府分裂民国,对此他也不以为然。维基百科说,一战后广州军政府曾打算让汪代表南方政府去参加巴黎和会,但他“对军政府不感兴趣,没有接受”。到二十年代孙中山转投沙俄,汪虽然赞成联俄联共,但反对接受共产党员以个人身份加入国民党。值得一提的是,除了刺杀这一次,汪最终都没有把自己的主张坚持到底,而是选择了服从领袖。

他和蒋介石二十年明争暗斗,分分合合的历史非常复杂,但根本上可以归结为他看不惯蒋那一套帝王术,也不认同蒋动辄以暴力解决纷争。

1927年四一二事变,蒋介石联合国民党西山会议派准备对共产党大开杀戒,汪坚决反对,与陈独秀在上海发表《联合宣言》支持容共,并不惜到武汉另立中央,谴责蒋武力清党行为,甚至宣称“反共即是反革命”。在各方压力之下,汪最后被迫退让,同意反共,并在年底尘埃落定之后宣布隐退,远走法国。

到1929蒋介石与各路军阀混战进入高潮,他又被反对派请回国内主持反蒋阵容,但最后因为张学良的东北易帜一败涂地,到30年底被迫亡命日本。未几蒋介石跟胡汉民因为约法问题闹翻脸,汪精卫力挺昔日同盟会老友,大骂蒋介石“暴横日甚,言之痛心”,二人遂在广东成立军政府,再次与南京政府对抗,并准备于31年九月北伐。

九一八事变的爆发促使汪精卫放下前嫌,再次与蒋合作,并于1932年初出任行政院院长,主持抗战中的政务。维基百科称汪在这一时期“抗日态度坚决,积极备战”。同年八月,汪精卫因为东北军不战而弃东北跟张学良翻脸,一再敦促他下野,并自请辞行政院长职;两个月后他查出患有肝硬化,再加上“外交、财政问题诸感棘手”,遂辞职赴柏林养病。越明年汪归国复职,开始主张并在蒋介石支持下主持对日和平交涉,自此越行越远。从1933年支持何应钦签订《塘沽协定》开始,他就开始成为主战派的眼中钉,背上卖国贼的骂名,并因此在1935年遇刺。虽然大难不死,但从此枪伤定期发作,而留在身体里的子弹,九年后到底还是要了他的命。

汪精卫性格的某些方面确实像极了他《送别》诗里那一片骄傲的枫林,不求追逐落日,宁愿放逐荒郊。他集子里像《送别》这类托物明志的诗不少。《咏菊》中说,“生也不逢时,落叶满天地。… 忍寒向西风,略见平生志。….  一花经九秋,未肯便憔悴。 ….  相逢应一笑,异代有同契”。以菊自许,但语气陈恳,清新自然,既不颓废,也无霸气,让人读来肃然起敬。《咏腊梅》里的 “古色最宜邀冻石,孤标只合耦冰仙”,表达的也是一肚皮不合时宜。

汪精卫反复多疑,徘徊摇摆的个性,在后期的诗中表现得淋漓尽致。比如他的名作《题易水送别图其二》:

少壮今成两鬓霜,画图重对益彷徨。

生惭郑国延韩命,死羡汪锜作鲁殇。

有限山河供堕甑,无多涕泪泣亡羊。

相期更聚神州铁,铸出金城万里长。

中间两联连用生典,在他的诗里并不多见。“生惭郑国延韩命” 自比战国后期为秦国修渠的韩国人郑国,明里说自己很惭愧,实则为解释曲线救国是有“延韩命”的苦衷 ;“死羡汪锜作鲁殇”又回到烈士主旋律,懊悔自己当年没能像鲁国的汪锜那样,马革裹尸以励国人。颈联画风再一转,安慰自己山河有限,国难当头,与其感伤堕甑、泪泣亡羊,不如砥砺前行。到结尾的“铸出金城万里长”,掷地有声,词藻气度俱佳,但虚张声势,言不由衷,境界到底落了下乘。

前面提过的《舟夜》,写于1939年,是汪精卫和周佛海等人在越南跟日本人谈判后,拟回上海推行和平运动,途中船上所作。后面四句曰,

良友渐随千劫尽,神州重見百年沉。

淒然不作零丁叹,检点平生未尽心。

颈联并无半分对自己铤而走险换来的“和平局面”的向往,反倒全是对神州人才凋敝,又将沉沦百年的无奈和感伤。但末句一转,似乎国事仍有转寰的余地,平生报国之心未尽,则残生尚有用武之地,未可轻掷。一首好诗,但写得如此纠结,不难想象诗人内心的挣扎和矛盾,嘴上虽说“不作零丁叹”,但心里大概是把惶恐滩走过好多遍了。

卿本佳人 奈何作贼?

这是所有读完汪精卫的人心头绕不开的终极追问。为什么? 他为什么要在抗战最艰苦的1938年,冒天下之大不韪,出走越南,去跟日本人和谈,而且一条道走到黑,最后被政府以叛国罪通缉,被党除名,也绝不悔改?

让我们先来做排除法。

第一,从汪精卫的性格看,我们知道他搞和谈肯定不是因为怕死。首先,他打小就悍不畏死。其次,到38年的时候,他已经年过半百,而且因为枪伤的缘故,活着了无生趣。为了半条残命卖国,似乎很不划算。最后,不搞和谈也不需要他上战场送死。跟着别人喊坚持抗战的口号成本并不高,他甚至可以带头喊。

第二,他和陈璧君出洋如家常便饭,万里来去自如。仅从这个细节看,他家不是一般的殷实。因此,贪财聚敛大概也不成其动机。

第三,从他三十年代不止一次主动要求下野的举动看,汪对权力的野心有限。至于指挥军队纵横捭阖,前面说了,他更是全无兴趣。

排除了贪生、求财和夺权这三点,剩下还有几种解释。

首先是汪精卫跟蒋介石的个人恩怨。汪精卫和蒋介石从孙中山去世之后就争斗不休,汪以孙中山接班人的身份,到抗战前只能勉强和蒋介石分庭抗礼,其后更是降格为蒋的副手,可谓屡战屡败,每况愈下。余英时以为 “以汪在党内的历史而言”,作蒋的副手是“相当让他难堪的“,并断言”蒋的唯我独尊必须对汪之出走负起很大的责任“。这个观点稍有诛心之嫌。也可能汪看不起蒋的人格操守,由此质疑蒋的决策是否出于公心。结果,蒋越是主战,汪越是认为他动机不纯。但不管出于何因,汪如此决绝地议和,一定程度上是受了蒋的某种影响,当无疑问。

其次,汪精卫觉得议和才是存国力、救黎民的最佳方案。事实上,那时候国内主和派并非只有汪一人,私下里觉得战必亡、和为上的人很多。客观而论,1938年欧战还没开打,抗日前景如何,国民政府在苏联、中共和日本三者之间,到底怎样取舍才能最好地平衡各方政治利益,最大限度保护民众,我相信除了毛主席和事后诸葛,没人敢说自己有把握能看清楚。但是,碍于舆论的高压,普通人怎敢公然把求和这种大逆不道的卖国言论说出口,平白给自己换顶汉奸帽子戴上?(注九)。

其三是胡适先生总结的“烈士情结“。简单地说, 汪精卫觉得自己非常人,应行非常事。普通人怕汉奸帽子,汪精卫一个民族英雄怎会把它放在眼里?我们的英雄诗人加职业革命家在这个万马齐喑的至暗时刻,“检点平生未尽心”,想起谭嗣同 “去留肝胆两昆仑”的敦敦教诲,念着当年发下的“残躯赴劫灰”的誓言,带着“我不入地狱谁入地狱”的执念,终于义无反顾地走上这条遗臭万年的单行道。

最后,汪精卫大概低估了在全面侵华已成事实之后再行和谈对中华民族形象和感情的伤害。汪一贯特立独行,从不轻易放弃自己的立场。他怼过孙中山,反过蒋介石,另立中央也不只一次。也许他觉得,孙中山跟日本人密谈过,拿着德国人的钱去广州搞军政府,最后还把老毛子请到家里来改组国民党,就这样也没耽误他老人家成就国父的一世英名。战和之间的分歧,也不过是人民内部矛盾,最多像当年的分共风波,或者中原大战,意见相左就先单干,就算再被开除党籍(注十),最终人们还是会理解他拳拳报国的一片苦心,还会请他回来的。

当然,最后这一次,他错了,而且错得一塌糊涂。事实证明,在民族国家时代,民族大义是意识形态领域里无敌的存在。一切敢于藐视它锋芒的人,无问东西,不论因果,都会被斩得魂飞魄散,永世不得翻身。

我儿子小时候特别不喜欢看书,但是不知何故对R. J. Palacio写的《Wonder『奇迹』》情有独钟。因为这个缘故我对书中的情节很熟悉,里面有句箴言印象深刻:

When given the choice between being right or being kind, choose kind.

我想了很久,觉得可以译为“宁入歧途,勿失慈悲“,就用这一句为汪先生作结吧。

 

聂宇

2023年12月4日, Wilmette, Illinois.

 

注释

注一:钱钟书有首作于1942年的《题某氏集》,

扫叶吞花足胜情,钜公难得此才清。微嫌东野殊寒相,似觉南风有死声。

孟德月明忧不绝,元衡日出事还生。莫将愁苦求诗好,高位从来谶易成。

这首诗后来被广泛认为是读《双照楼》后写的诗评。钱先生喜欢挖苦知识分子矫揉做态。《围城》里汪处厚续弦后,早已想好“眼前新妇新儿女,已是人生第二回”的佳句,只恨新太太尚未生养,一时用不上。所谓“莫将愁苦求诗好”,无非是讽刺汪精卫也不过是“为赋新词强说愁”罢了。

注二:这段故事维基百科中未见记载,我是听人民大学张鸣教授讲的,说他和黄复生(四川隆昌人,算是我半个老乡)被捕后都坚称自己是主谋,对方是从犯,让主审官颇为感佩。另外,汪精卫行前已报必死之心,有《致南洋同志书》称:“此行无论事之成败,皆无生还之望。即流血于菜市街头,犹张目以望革命军之入都门也。”

注三:据维基百科记载,日本投降后,1946年1月21日何应钦奉命将汪墓炸毁,并将遗骨送往清凉山火葬场火化,骨灰被抛到长江里。

注四:汪精卫在狱中听说胡汉民在黄花岗起义中牺牲后写下三首五律,这是其一。后来发现是误传。

注五:南明张煌言的《入武林》一诗作:

家亡国破欲何之?西子湖头有我师。日月双悬于氏墓,乾坤半壁岳家祠。

惭将赤手分三席,拟为丹心借一枝。他日素车东浙路,怒涛岂必属鸱夷。

注六:12年辛亥之后去法国读书,13年二次革命失败之后去法国避难,19年巴黎和会前后,27年因为分共和蒋介石闹翻后出走法国,还有32年底和35年底两次去欧洲治病。

注七 据维基百科,“汪与吴稚晖在巴黎时,曾经有一次,吴氏手里捧著一顶军帽,很严肃地献给汪,他说:“你戴上吧!今后要革命,要救国,要实现主张,要贯彻主义,一定要依靠武力,我希望你成为一个军事家,来领导同志。你如能挺身以当大任,我第一个就愿意向你磕头。”“但汪表示他对军事没有兴趣。

注八 “眼底沧桑”,正版应为“眼底风光”。余英时考证,汪本拟作“沧桑”,后以过于颓废改为“风光”, 余以为“沧桑”与全词格调更合,故从其原意。

注九 余先生的序里提到,陈寅恪即持此论。另外汪精卫在河内发表呼吁终止抗战的“艳电”之后,曾致电孔祥熙解释动机:

弟此意乃人人意中所有,而人人口中所不敢出者。弟覺得緘口不言,對黨對國,良心上,責任上,皆不能安,故決然言之。前此秘密提議,已不知若干次,今之改為公開提議,欲以公諸同志及國人,而喚起其注意也。

余先生说汪精卫所言“弟此意乃人人意中所有,而人人口中所不敢出者”,确为事实。

注十: 据维基,在1939年因为投日被开除党籍之前,汪1925年曾被西山会议派开除党籍,以及在1930年中原大战期间被开除党籍。

The song of Achilles

I read The song of Achilles about two years ago, wrote a short review then but never got the chance to post it here.  This is one of the few fiction books I have read cover to cover  since I turned 40 – thanks to my daughter’s recommendation.


My 11-year-old daughter fell in love with Greek mythology lately and has filled her bookshelf with the likes of Percy Jackson and Trials of Apollo.  Frustrated with my complete ignorance of the subject, she tried repeatedly to get me to read some of her books.  She marveled at The Song of Achilles all the time and insisted I must read the book because it is simply “too good” to pass over.  Eventually, I caved in despite my reluctance—novels have largely ceased to interest me, let alone a novel about Achilles, whose story has become a cultural cliché, even in China. Who could forget about the heels that his mom famously failed to wash in the magic spring?

It turns out I enjoyed the book more than I thought I could.  Madeline Miller made me constantly guess the theme of the book, but she managed to outwit me at every turn.  Initially, it seems that the book is about the love between two young men: Achilles and I the narrator (Patroclus). Then, I thought the focus is the insanity of the Trojan war, and how it transforms an innocent boy into a monstrous killing machine.   At one point, Miller mocked nationalism and advocated humanitarian principles, when she proclaimed through Chiron (a centaur) “nations were the most foolish of mortal inventions” and “no man is worth more than another, wherever he is from”. Eventually, I realize the central plot may be the ancient conflict between a jealous mother and her son’s spouse (a son-in-law in this case).  Achilles’s mom, Thetis, refused to endorse his relationship with Patroclus till the very end, even after they are buried together.   In the eyes of the jealous mom, Patroclus is an unattractive mortal unworthy of Achilles, a man who cannot bear an offspring for him, and above all someone who committed the unforgivable sin of sharing the love of her son.  But more fundamentally, Thetis and Patroclus fought hard to bring about a different Achilles in the book: Thetis wants a god-like, ruthless warrior, while Patroclus prefers an empathetic, creative human.  It seems to me this discrepancy, not the Prophecy, finally sealed the tragic fate of the couple.

Having finished the book, I must say I don’t quite understand why my daughter and her friends like it so much.  It is a book written for adults, with contents that I imagine some parents might find objectionable for kids of her age.  I know for a fact in my generation such a book would be considered off limits for 11-year-old. But, hey, we live in a different age, don’t we?

Is competition for losers in bikesharing?

The rise and fall of the bikesharing industry in China offers a cautionary tale about the risks of an unregulated market with a low entry barrier. It is well known that, while low entry barriers can promote competition and innovation, they may also lead to higher market volatility and potential challenges in achieving profitability due to intensified rivalry . There are also limited economies of scale to be had, making it exceedingly difficult to establish a monopoly. As Peter Thiel noted, “competition is for losers”‘ in such markets and good entrepreneurs should simply stay away from them.   However, writing off the bikesharing industry as unprofitable cannot be the only story here. After all, bikesharing has a genuinely positive societal impact and should have its place in many of our cities that are haunted by the disease of auto-dependency. The question is what, if anything, can be done to foster a healthy bikesharing market that is attractive to both users and private investors.  We set up to answer this question here.  You may download a preprint here, or read the abstract below.


Abstract: We model inter-operator competition in a dockless bikesharing (DLB) market as a non-cooperative game. To play the game, a DLB operator sets a strategic target (e.g., maximizing profit or maximizing ridership) and makes tactical decisions (e.g., pricing and fleet sizing). As each operator’s payoff and decision set are influenced by its own decisions as well as those of its competitors, the outcome of the game is a generalized Nash equilibrium (GNE). To analyze how competition may shape the choice of strategic targets, we further augment the game framework with a ranking scheme to properly evaluate the preference for different targets. Using a model calibrated with empirical data, we show that, if an operator is committed to maximizing its market share with a budget constraint, all other operators must respond in kind. Otherwise, they would be driven out of the market. When all operators compete for market dominance, Moreover, even if all operators agree to focus on making money rather than ruinously seeking dominance, profitability still plunges quickly with the number of players. Taken together, the results explain why the unregulated DLB market is often oversupplied and prone to collapse under competition. We also show this market failure may be prevented by a fleet cap policy, which sets an upper limit on each operator’s fleet size.

Solomon’s Ring

Legend has it that King Solomon’s ring, also known as the Seal of Solomon, conferred on him the ability to command the supernatural and to speak with animals.  Despite the enticing title, the book has nothing to do with King Solomon and his famous ring, or Jewish history, or the Israel-Palestine conflict (since this topic is on everyone’s mind these days…).  Instead, it consists of interesting stories about the animals that the author raised to observe their behaviors.  Widely considered “the father of ethology”, Konrad Lorenz won Nobel Prize in Medicine in 1973 for his foundational contributions to the study of non-human animal behaviors.  King Solomon’s Ring, published in 1949 and written for a popular audience, remains his best-known book.  Lorenz was a controversial figure due to his association with Nazism, which apparently came to light only after his death.  According to Wiki, not only was Lorenz a Nazi, but he served as a psychologist in the notorious Office of Racial Policy during the war.  In his application for the party membership, Lorenz pledged to devote “his whole scientific work to the ideas of the National Socialists”.  That said, I found no racial slurs, dog-whistles or anything that can be construed as remotely antisemitic or hateful in the book.   Quite the contrary, the book was a relaxing and enjoyable read that made me giggle more than any book in recent memory. Beyond fascinating facts about animals, the reader will also be confronted with thought-provoking questions concerning human nature and the relationship between men and animals.

Lorenz described many species of animals that he kept in and around his home, ranging from fish and birds to dogs and monkeys.  Notably, he did not keep these animals in captivity but instead let them – to the extent possible – freely wander around on his property, even in his office.  In some sense this was the mandate of his work, since only free ranging animals can “be themselves” and thereby reveal their natural behaviors. However, to Lorenz these animals were more than just a research subject.   He lived with them, bonded with them, and cherished their company.   He saw humanity in these animals – or animal traits in humans, depending on your perspective – because humans, in a quite literal sense, are their descendants.   As a result, his writing adores and humanizes them.

I was never a big fan of animals. Growing up in a small and poor city in China, where few families keep pets in their home, I was naturally disposed to be afraid of most animals, including dogs and cats.  Yet, I think even I would find the gaze of Lorenz’s beloved dog, named Tito, irresistible.  Tito was an Alsatian (or German Shepherd), famous for being “exaggeratedly faithful”.    Lorenz recalled that Tito would remain lying at his feet for hours and hours as he works at his desk, and

she was far too tactful to whine or to call attention to herself by the slightest sign. She just looked at me. And this gaze of the amber-yellow eyes in which was written the question “Are you ever going to take me out?”, was like the voice of conscience and easily penetrated the thickest walls.

Lorenz injected a delightful sense of humor into his storytelling that is truly infectious. I remember several instances when I laughed so loudly in my office that people in the hallway could probably hear me.   His vivid account of the territory-setting battle between two stickleback fish was a great example.  He wrote, describing how the distance from a male fish’s nest is a reliable predictor for the strength of not only his will, but also his actual ability to defeat his rival,

In the immediate neighborhood of his nest, even the smallest male will defeat the largest one…. The vanquished fish invariably flees homeward and the victor, carried away by his successes, chases the other furiously, far into its domain. The further the victor goes from home, the more his courage ebbs, while that of the vanquished rises in proportion. Arrived in the precincts of his nest, the fugitive gains new strength, turns right about and dashes with gathering fury at his pursuer. A new battle begins, which ends with absolute certainty in the defeat of the former victor, and off goes the chase again in the opposite direction.

On another occasion, Lorenz saw a father jewel fish accidentally swallow, at the same time, his own baby—a duty he routinely performs to save his children from drowning—and an earthworm, his favorite food. The father thus faced a dilemma, as in his mouth were two different things “of which one must go into the stomach and the other into the nest”. Lorenz recalled with amusement what unfolded next,

The fish stood stock still with full cheeks, but did not chew. If ever I have seen a fish think, it was in that moment! … For many seconds he stood riveted and one could almost see how his feelings were working. Then he solved the conflict in a way for which one was bound to feel admiration: he spat out the whole contents of his mouth: the worm fell to the bottom, and the little jewel fish, becoming heavy in the way described above, did the same. Then the father turned resolutely to the worm and ate it up, without haste but all the time with one eye on the child which “obediently” lay on the bottom beneath him. When he had finished he inhaled the baby and carried it home to its mother.

Using his jackdaw bird colony, Lorenz repeatedly explores what appears to be an important theme of the book: the similarities and differences between human and animal behaviors.

He observed how jackdaws teach their youth about the danger of the enemy by making a rattling sound in response to a dangling black object in sight. This is remarkably “human” for two reasons. First, knowledge is passed on to the next generation through “learning” rather than “inheritance”. Second, like jackdaws, humans also fall victim to such blind, instinctive reactions (the black object). I am certain Lorenz had his former Fuhrer in mind when he asked,

“Do not whole peoples all too often react with a blind rage to a mere dummy presented to them by the artifice of the demagogue?”

Lorenz observed that a “married” jackdaw couple would not only take each other to love and to cherish till death do they part, but also, apparently, maintain “the glowing fires of the first season of love” throughout their marriage.    Even after many years, he wrote, “the male still feeds his wife with the same solicitous care, and finds for her the same low tones of love, tremulous with inward emotion, that he whispered in his first spring of betrothal and of life”. At first glance such a relationship feels amazingly human; but if you pause and think again, you realize it is in fact quite nonhuman, if not superhuman.  Although humans may live in a life-long marital union, Lorenz lamented, they tend to forget “the thrilling enchantment of courtship’s phrases entirely” as time goes on, and only perform the ritual of their marriage “with the mechanical apathy common to other everyday practices”.

It is well known that a definite order – by which each animal is afraid of those above them in rank – exists in many social animals.  Lorenz’s jackdaw colony is no exception. The interesting twist is that a female jackdaw can acquire a higher rank by marrying a male who ranks above her – a social mobility that is, unfortunately, not available to a male (again, how very human this is!).  If the bird marries the king, she will be granted by every member of the colony the status of a queen.  When this happens, the news of the marriage, and hence the promotion of the wife, spreads quickly in the colony. The funniest part of the story is how the newly crowned queen, having suddenly risen far beyond her own station, would “conduct herself with the utmost vulgarity” when she encounters other jackdaws whom she must look up to only a few days earlier:

She lacked entirely that noble or even blasé tolerance which jackdaws of high rank should exhibit towards their inferiors. She used every opportunity to snub former superiors, and she did not stop at gestures of self-importance, as high-rankers of long standing nearly always do.

Establishing a pecking order is one way by which social animals resolve conflicts without suffering excessive casualties. Lorenz mentioned another mechanism that I shall call the surrender’s inhibition.  According to this law, a victor emerging from a bloody battle for dominance would be inexplicably “forbidden” from hurting the loser, as long as the latter surrenders, i.e., offering to his adversary the most vulnerable part of their body as a submissive gesture. Humans evidently have inherited the habit of making submissive gestures (e.g., kneeling and bowing) when facing a dominant aggressor. Unfortunately, such an appeal to mercy is not as failproof among humans as in the animal world. Homer’s heroes, noted Lorenz, often killed supplicants “without compunction”.  Bai Qi, a Qin Kingdom general, killed 400,000 surrendered soldiers after the Battle of Changping, a prelude to the kingdom’s brutal campaign to unite China under imperial rule.  Mongols, of course, had an abhorrent reputation for indiscriminately slaughtering entire cities of people when they faced even the slightest resistance during their conquests. Nor do we have to go back to primeval or medieval times for the evidence of our species’ sub-animal barbarity.  About three weeks ago, on October 7th, 2023, Hamas militants invaded Israel and killed more than 1,000 civilians, including many children and elderly – many of the victims, I imagine, would have begged for their lives, but to no avail. Why?

Lorenz argues that the surrender’s inhibition is a result of evolutionary adaptation.  That is, for a species to survive, it must develop a social inhibition to prevent the abuse of its lethal weapon which could endanger the existence of the species.  However, we humans make our weapons “of our own free will” rather than grow them on our bodies as dictated by nature.     Because human weaponry developed so rapidly relative to the time scale of evolution, our instincts could not keep up with it, leading to a lack of adequate inhibition in its usage.  There is a certain truth to this argument.  However, humans also have far more reasons to murder the members of their own species than the imperative of survival. Ideology, for example, offers a powerful motive for mass killing infidels, heretics, or those who happen to have an intolerable identity.  In the end, Lorenz expressed optimism that humans can learn from animals, that if anyone slaps us on the right cheek, we should, as Bible teaches us, turn to him the other cheek also.  This is not so that our enemy may strike us again, explained Lorenz, “but to make him unable to do it”.  I admire his faith in humanity and wish he was right, but I am deeply skeptical whether this age-old wisdom would have saved anyone who was killed by Hamas fighters on October 7th.

RIVER published.

The last paper I wrote with  Kenan Zhang, who graduated two years ago and is now joining EPFL as Assistant Professor, was finally published in Transportation Research Part B last week.  The paper first went on-line at SSRN in December of 2021.  So, it has been in the review process for nearly two years, during which it was reviewed by three different journals.   I am relieved the paper is finally in print; I know Kenan was exhausted by the lengthy back-and-forth with reviewers and editors.  Rewarding as the experience may be, one can only take so much for each paper without being demoralized.

The above link should work for two months.  After that, if you don’t have access to the journal, you may find a preprint here.