After the midday rest, I was at least back to my usual level of energy. The world no longer appeared blurry and indistinct. This was the first general education class, where I’d meet animals from other departments. But only about a dozen animals had registered for the course—probably because of the late time slot.

"Hello, everyone. Welcome to the core sociology general education course, Diverse Gender Identities." The instructor, a female Thomson's gazelle, deftly operated the electronic podium. "Some of you may not be sure how to pronounce the course title," she said as the words “Diverse Sex/ual Identities” appeared on the projection screen. "It's pronounced as ‘Diverse Sex and Sexual Identities.’”

Alright, so that's how it's read. But it only made me more confused. Gender has diversity too? Actually, I’d never really thought about this issue.

Turner syndrome, XXY mosaics, androgen insensitivity syndrome… Whether in terms of genotype, phenotype, or appearance, sex cannot be neatly divided into male or female. Given these conditions, it’s completely reasonable that gender identity isn’t binary either.

I tapped my nails on the desk, sensing the various scents of confusion around me. For ordinary animals, this might be understandable, but I, who not only knew about these sex-related genetic polymorphisms but was also a hybrid of the ultimate taboo—a life animal and a nature animal—had never thought about something so simple before.

"This is our course outline. Since this is a core sociology course, we'll start by discussing how the origins of sociology—philosophy—have influenced the fields of diversity and diverse gender identities.

After that, we'll explore some major contemporary issues and achievements in this field. The course will include some field visits and interviews, and the highlight will be participation in and observation of a social movement.

We haven’t yet decided on the theme of this year’s social movement, as several issues are on the verge of boiling over in Central City, including environmental protection, labor rights, animal rights, and the right to survival. However, barring unforeseen circumstances, the theme will be announced after our guest lecture in the third week.” She switched to the next slide.

“Now, let’s delve into today’s topic: the foundation of all disciplines—philosophy.” The teacher scanned the classroom as if building some sort of atmosphere. I’d heard this claim before, but I still didn’t quite understand why philosophy was considered the mother of all disciplines.

"I won’t be talking about things like ‘If not P, then Q’ or other tongue-twisting concepts here. Let’s dive right into a recent popular and classic thought experiment." The projection screen displayed a white fox standing behind a lectern, with the large, bold red title “Justice” above its head.

Recently, the bookstore shelves had been filled with books on this topic. I had skimmed through a few, but I still didn’t quite understand why such a journey of contemplation was called justice.

“Let’s begin with the classic version of this famous thought experiment, although it has many variations.” The screen now displayed a trolley and two sets of tracks.

“Today, you’re on a trolley, all by yourself. Ahead, on the track, five animals are tied up and unable to move. You can’t stop the trolley in time, but you can pull a lever to switch tracks. However, if you do, the trolley will move onto another track, where one animal is also tied up. So, would you pull the lever to switch tracks?”

The classroom fell silent at the teacher's question. This wasn’t quite as tricky as being asked who you’d save first, your mom or me, if both fell into the water. But for most animals, genuinely putting themselves in this thought experiment would still present an agonizing dilemma.

"Do we know anything about the animals tied up, like what species they are?" asked a zebra from another department.

"No, you have no additional information. You only know for certain that there are five animals on one track and one on the other," the teacher replied, and the zebra fell silent again.

The subtext was practically bursting out, but whatever. In situations like this, knowing more doesn’t actually help—it just gives the illusion of having more bargaining chips. More information doesn’t make the decision any easier.

The room remained quiet. Come on, people. Aren’t you noticing that the trolley is still moving?

"I would pull the lever to switch tracks," I said.

"Could you explain why you would do that?" the teacher asked, and all eyes turned toward me.

“When there’s no other information available, and I’m the only one who can make a choice, I must minimize the harm. Five lives outweigh one,” I replied, my tone colder than I intended.

"How can you think that way? By pulling the lever, you're effectively killing that one animal. Those five were going to die anyway. I wouldn’t touch the lever,” someone said. I didn’t even bother to look at who spoke.

“There’s no such thing as ‘were going to.’ You’re choosing to abstain from intervention. What you’re doing is called ‘inaction.’ You’re not doing nothing or let fate take its course. Those five animals would die because you chose not to act—not because they were destined to. Free will is what matters most: making a choice and taking responsibility, rather than imagining some higher force pulling strings and us helplessly dancing to its inscrutable will.”

My tone was too detached and cold—damn it. If I scared them, it would defeat the purpose of having a thoughtful discussion. Try speaking on equal footing, with mutual respect!

"I don’t think I could decide to switch the trolley’s path," said a Himalayan hare, offering a faint smile. "I wouldn’t be able to bear the responsibility of another animal's death. Even if I know that not switching is equally my responsibility, I think I’d be too weak to make such a decision. I’d just watch the trolley move forward helplessly. I envy animals with stronger wills."

"Maybe rabbits can’t pull the lever anyway, so they can’t switch the trolley," a lion quipped. Several animals laughed, though I didn’t get the joke.

“In this thought experiment, the trolley will switch tracks as long as you intend it to,” the teacher clarified, explained what a thought experiment actually is..

"Then, of course, I’d switch the trolley," said the lion. "Five lives are always worth more than one. Every life is equally important, no matter what species they are.” He grinned at the zebra, making his pointed intent clear.

“If every life is equally important, then why do you think five lives outweigh one?” asked an African elephant sitting quietly in the back, who hadn’t spoken until now.

“Huh?” The lion’s confusion was evident in his tone.

"If every life’s value is immeasurable and infinite, how does five outweigh one?" The elephant spoke slowly and steadily, with an almost infinite patience.

“There must be a way to quantify it. It’s impossible for every life’s value to be exactly the same,” the lion replied, scratching his ear.

“Leaving aside what standard you’d use to quantify value, didn’t you just say all animals’ lives are equally important? Under that premise, five lives wouldn’t necessarily outweigh one,” the elephant countered.

These colossal animals always exude a certain aura of wisdom when they speak, a presence so profound that even life animals can't help but feel awed.

“But if you have no other information and must make a decision, you have to assume all animals’ values are equal,” the lion tried again to argue his point.

“Five times infinity is still just infinity,” the elephant calmly concluded. Was this elephant a math major or a philosophy major? Wait, philosophy majors can’t take this class.

"Alright, everyone, we've just heard a lot of different perspectives," the teacher said as they switched to the next slide.

"Many of these ideas belong to more specific branches of philosophy, but that’s not the focus of our lesson today. Broadly speaking, we can categorize your thoughts into two main schools: 'All lives are equally important' and 'Choosing the lesser of two evils.' These perspectives correspond to two philosophical schools: deontologists and utilitarians." Statements began appearing on the slide one by one.

"To simplify, deontologists believe that all lives are equally important. Therefore, it is wrong to price or evaluate lives in any way. Regardless of what someone has done or their identity, their intrinsic value remains unchanged. Utilitarians, on the other hand, believe that as long as the overall benefit outweighs the cost, the action is justifiable and correct." The next slide showed an illustration of a trolley with multiple tracks.

"This is why the trolley problem has many variations. Some of you have already mentioned one: What if the animals on the track were five life animals and one nature animal?" The teacher raised a sensitive question, and the classroom atmosphere grew a bit tense.

"Then I’d protect the nature animal," the zebra who spoke first said softly. The lion rolled his eyes exaggeratedly, so much so that everyone probably noticed. "What? You life animals wouldn’t understand what it’s like to constantly face the threat of sudden death as a nature animal. Given this rare opportunity to choose—something I’ve never had the power to do before—of course I’d protect the nature animal," the zebra said, shooting the lion a sideways glance to make her point.

"Although this might sound a bit strange for me to say," a sharp, high-pitched voice chimed in—it was a small forest mouse—"I think if the combined life expectancy of the five animals exceeds that of the one, then we should sacrifice the one with the shorter life expectancy."

The mood became heavy, a hallmark of university-level discussion-based teaching. Damn it, I was starting to feel excited about it.

"This perspective leans more toward utilitarianism. Now, let’s consider another variation. Imagine you’re not on the trolley but instead watching it hurtle toward five animals tied to the tracks. Beside you is a massive elephant," the lion smirked theatrically at the large elephant sitting at the back of the room as the teacher continued. "You’re certain that if you push the elephant onto the track, the trolley will stop. Would you do it?" The teacher paused, and silence filled the room.

"I think I should be more worried about that elephant throwing me onto the track," the lion concluded. Everyone laughed, even the African elephant.

"Alright, let’s consider a more feasible scenario. Imagine you’re a doctor, and a perfectly healthy animal comes in for a routine check-up. Meanwhile, you have five other patients who need critical organ transplants, which could be obtained from the healthy animal. Would you sacrifice one healthy animal to save five sick ones?" The teacher glanced around the room, offering an encouraging smile.

"Although the Hippocratic Oath explicitly forbids such actions, and carrying them out in practice would severely undermine trust in medical institutions—clearly causing more harm than good—I think I understand the parallels between these thought experiments," I said while reflecting. "So, if I were a utilitarian, I’d have to accept this seemingly absurd scenario, right? As long as the final benefit outweighs the cost, a true utilitarian would agree. Conversely, a deontologist, who believes that life’s value is immeasurable, would refuse to make the trolley switch regardless of the number, species, or past deeds of the animals involved. Inconsistent decisions in similar scenarios would indicate a logical contradiction, suggesting either a lack of a guiding principle or a fundamental misunderstanding of oneself—a life lived under the illusion of self-awareness." I began to grasp the logical progression.

"That’s one way to summarize it. But it’s important to note that the trolley problem is merely a tool for examining the logic used by utilitarians and deontologists. It’s not meant to dictate real-life emergency decisions. Of course, there are many variations and philosophical nuances to explore, which might be covered in your general philosophy core courses. What I want to highlight here is another interesting point: What relevance does the trolley problem have to us? After all, we’re unlikely to face such scenarios." The teacher moved to the next slide, which showed a sinking ship and a car about to hit pedestrians.

"In 1884, there was a shipwreck involving the Mignonette. Three surviving life animals—a hyena, a crocodile, and a jackal—killed and ate a zebra after running out of food. The three survivors were sentenced to death but later pardoned and given prison sentences instead. This incident led to the clear establishment of a rule: Necessity cannot be used as a defense against murder in emergency situations.

If this sounds familiar, that’s because it inspired the story of Life of Pi," the teacher explained. Many students, both nature and life animals, looked shocked. These events are secret historical incidents that typically only the Beast and the most outstanding selected students are privy to*. For animals experiencing the shattering of their perceived surface harmony for the first time, the impact was profoundly intense.

"See? I told you tigers aren’t the worst shipwreck companions," said the Bengal tiger who lived on the floor below me, breaking the heavy atmosphere and making everyone laugh. I hadn’t even noticed he was taking this class too.

"Even so, that example still feels distant. Let me share something more contemporary. Autonomous vehicles are now in the testing phase. As manufacturers designing cars for consumers, the default programming of autonomous systems prioritizes passenger safety over pedestrians. Is that fair?" The teacher posed another question, and the students resumed their discussions. Some were horrified by the cold logic of such programming, while others expressed deep trust in data-driven decisions.

So, this is what critical thinking means. I think I’m beginning to understand why the book is called Justice. What sparks will emerge when different values and experiences collide in dialogue?

I could feel something changing within me.

After dinner, I returned to my dorm room and sat down at my desk, opening my laptop.

The student cafeteria was conveniently located on the first floor of Seventh Student Dormitory. The prices were quite affordable, especially for a place like Central City, where the cost of living was notoriously high. However, this convenience seemed to have greatly limited my range of activities. It had been a while since I last read a book. Maybe I should visit a bookstore sometime—there’s supposed to be one in the district next to the campus.

I reflected on the events of the day, tapping my head lightly. Then, I opened my browser and searched for videos about Justice on Beastube. The results were flooded with speeches by a white fox.

In this era, where all information is just a three-second search away, what kind of impact will it have on the future? The cost of acquiring knowledge has been drastically reduced. As long as an animal knows how to use the internet, they can immediately dive into unfamiliar topics. The barriers to communication and participation in public discourse have disappeared. With so many new possibilities converging, what lies beyond the final obstacle? What kind of scenery awaits on the other side of the hill? I’m dying to find out.**

I shifted my focus back to the browser. Videos of speeches related to Justice were indeed incredibly popular; even versions translated into the universal language had been uploaded in large numbers. I clicked on the Harvard Open Online Courses version.

“This is a course about justice,” the white fox said, pacing across the stage. “And we begin with a story...”