As finals approach, I’ve been hired as a grader for my advisor’s Intro Philosophy class.

I love these classes, where we’re trying to give students a taste of everything: here’s a little skepticism, a little political philosophy, a little meaning of life. All the while, students are scrambling to figure out what the hell philosophy is.

And that’s not all, because for many students, Intro Philosophy functions as the English class they never got. They need to figure out how to read carefully, how to argue clearly, how to write convincingly.

And boy do sixteen weeks go by fast.

Since I have to turn on that part of my brain anyway, here are 3 mistakes I see over and over again in Intro Philosophy:

1. Unclear thinking → Unclear writing

It happens all the time: An Intro Philosophy student writes a paper they think is clear, but only because they wrote it. But then when anyone else reads the paper, they’re left with a ton of questions.

Writing clearly is hard. We have to identify and expose our own assumptions to help others follow our ideas. That’s emotionally vulnerable work that takes a lot of time and self-reflection.

Not surprisingly, there are a lot of levels at which it can go wrong:

Sometimes, the content is unclear. Students will say things like “Mill is basically all about happiness,” and move on to the next idea. But wait, I still don’t know what that last sentence means!

If you can’t explain the basics clearly, you probably aren’t so clear on them. I tell students that I imagine writing for my dad, which means I need to explain any jargon and motivate the underlying problem in plain English. So why not show a draft to your roommate before you turn it in, and ask them to underline anything they don’t understand? Other times, the sentence-level writing is unclear. Students sometimes think I want them to go for baroque: “Since the dawn of time, moral rumination has been acutely indispensable…”

Just talk out loud and write what you say—there’s your first draft. And when you’re done fixing it up, why not read your words back out loud to hear how they sound? If you’re lazy, Microsoft Word can even do it all for you, dictating what you say and reading your words aloud to you! And of course, sometimes the overall structure is unclear. How did you write a three-page-long paragraph without getting lost? How am I supposed to read it? You can give students suggestions:

• Your thesis should say something like “I will argue X because Y,” so I get a sense of where the paper’s going, and you get to tell me what you want to be graded on.

• Each new idea should get its own paragraph.

• The last sentence of one paragraph should lead smoothly into the first sentence of the next.

Rules of thumb like this can definitely help. But students still have to get out there for themselves and just start trying stuff to see what does and doesn’t work. Writing’s hard.

2. Naïve relativism

Moving to content: I’m always surprised by how often students slide from questions of epistemology (roughly, what we know) to questions of metaphysics (roughly, how things are). Sometimes, students argue that because we don’t or can’t know something, there’s no right answer. But this can’t work. Maybe we can’t know whether there was an odd or even number of red pandas at the turn of the twentieth century. Does that mean there’s no right answer?!

Sometimes, students even move from the obvious fact that we disagree about something to the bizarre conclusion that there’s no right answer. Well, different cultures disagree about what’s morally right or wrong. I guess it’s allll relative.

I think this is a well-intentioned move to avoid prematurely judging other cultures that we don’t understand. But it ends up exoticizing other cultures by treating them as so thoroughly alien and estranged from our own that we can never enter into meaningful ethical dialogue with one another.

Indeed, this sort of naïve relativism estranges us from our own past. Not so long ago, slavery was so central to American culture that we fought a huge war over it. Today, enough of us agree that slavery is bad that I can use it for this example. But if relativism is true, that’s not a case of actual progress. Folks back then followed what 19th century society said was right. Folks today follow 21st century society. That’s just another tie! You’re not a relativist. You’ve just misdescribed your own view, and that’s understandable. Philosophy’s tricky. That’s why we’re here.

3. The naturalistic fallacy

Here’s an argument:

1. X is natural

2. Therefore, X is good

Now apply it to whatever you want:

• X = being selfish

• X = eating meat

• X = natural disasters

This argument doesn’t work. It’s called the naturalistic fallacy, and it faces a whole slew of devastating objections. First off, X can be natural and bad. If you’re Christian, you’re already familiar with the idea of Original Sin. Human nature is sinful. And that’s bad, not good! Second, just because X is natural doesn’t mean it’s inevitable. We might be able to fight against or even change nature. If being selfish is bad, maybe you should fight against your natural selfish impulses? Maybe that could even make you less selfish over time? And finally, how do you know X is natural? These sorts of judgments are notoriously culturally bound. The early Confucian philosopher Mengzi argues that human nature is basically empathetic. If we saw a kid fall into a well, everyone would rush over and try to help them, right? But in a capitalist society, we tend to think of human nature as selfish instead. Hmm, I wonder if my unchecked intuitions about what’s normal and natural have been conditioned by my society in any way. Yeah, probably! So welcome to philosophy, I’m glad you’re here. And I hope you stick around.