Kodi Arfer / Writing


For original research, see my projects page.


The unlived philosophy is not worth having

150 words • Created 27 May 2015 • Last modified 19 Aug 2022

Doing good philosophy isn't just a matter of saying the right things on paper or in a classroom. It's a matter of fulfilling your philosophy in your thoughts and actions.

What is the meaning of life?

1,000 words • Created 12 Aug 2012 • Last modified 24 May 2020

Why I'm a psychologist and why I think ethical standards should be kept reasonably low.

Valedictory address

1,000 words • Created 3 May 2011

Allegheny College's class of 2011 had three valedictorians: yours truly, Zach Piso, and Kimberly Fierst. On 3 May 2011, at an awards ceremony about two weeks before graduation, Zach and I delivered a joint address on the vague theme of intelligence. The subject matter is very heterogeneous for such a short speech, but I like how I managed to explain everything that I thought was really big and really important in three paragraphs.

My political views

1,500 words • Created 23 Aug 2020 • Last modified 30 Mar 2023

A concise description of what rules I think society should follow. I'm a leftist and a pacifist, and I emphasize science and health in my view of the role of government.

The right to complain

150 words • Created 8 Sep 2009 • Last modified 7 Jan 2015

A statement that everyone deserves compassion.

Censorship and its limits

350 words • Created 31 Aug 2015 • Last modified 28 Nov 2022

Censorship is valuable and necessary, but must be applied judiciously. Peddlers of bigotry and other bad ideas shouldn't be universally and unconditionally ostracized.

The fine line between disability and vice

700 words • Created 10 Aug 2014 • Last modified 22 Aug 2022

The difference between qualities we think people deserve (like laziness or kindness) and the qualities we think people are merely subject to (like blindness or perfect pitch) is often indistinct. I argue that the practice of doling out praise, blame, punishment, and reward on the basis of whether people really deserve it is ultimately counterproductive.

Belief and truth

Against experience: The perils of relativism

4,000 words • Created 23 Aug 2014 • Last modified 22 Aug 2022

I discuss a common thread in a wide variety of social problems, which is skepticism towards the notion of objective truth and reverence towards personal experience. These problems include pseudoscience, pseudomedicine, belief in the supernatural, political conspiracy theories, questionable philosophies and policies in the name of social justice, questionable educational practices, and a lack of concern for the consequences of one's own life. If we want to make the world a better place, we should believe in the world.

Belief is value-dependent

350 words • Created 10 Apr 2015 • Last modified 8 Dec 2015

Even formal methods with optimality guarantees, particularly statistics, are not enough to completely determine how observations should affect our beliefs. We also need certain assumptions about how to value beliefs, such as what mistakes we'd rather make. This state of affairs is bad for empiricism and science, but not fatal.

My dualism

900 words • Created 3 Oct 2009 • Last modified 27 Apr 2017

An attempt to reconcile my materialist tendencies, particularly when it comes to the philosophy of mind, with my belief in the primacy of mathematics.

Overcommitment and being informed

400 words • Created 2 Jan 2015 • Last modified 8 Dec 2015

You only have time to do a few things. In fact, you only have time to understand a few things.

A pragmatic view on gender and transgenderism

600 words • Created 29 Mar 2015 • Last modified 17 Jun 2017

Are male-to-female transgender people really female? Are nonbinary gender identities real? I argue that actually, these questions don't make sense. Our real concern when it comes to controversial gender identities should be concrete questions like "What information should be recorded on a birth certificate?" and "How should bathrooms be segregated (if at all)?". Considering practical matters like these on their own terms makes it clearer that whether or not somebody is "really" a woman is of no significance.


Empirical Sexual Attitudes

30,000 words • Created 10 Feb 2012 • Last modified 24 Jan 2023

A short book on the psychology of sexuality. Its goal is to determine what sexual attitudes we should endorse if we want our attitudes to be as faithful as possible to the available empirical evidence. I've aimed to make the book scientifically rigorous but also accessible to a general audience.

The unfulfilled promise of art

2,000 words • Created 16 Jan 2013 • Last modified 7 Jan 2015

I argue that the common assumption that art is good and necessary is unjustified. The case for why we should promote art is dubious, and I worry that art can be profoundly distracting.

Vicarious restraint

400 words • Created 23 Jan 2011 • Last modified 14 Aug 2012

A cynical hypothesis to explain why smut (sex, violence, drugs, and so on) are characterized as "adult": because describing smut as inappropriate for children comforts adults about the dangers of smut without requiring adults themselves to forgo such guilty pleasures. Note that the experiments I've run so far have been unsupportive.

Why psychotherapy is so weird; or, One problem with the crazy leading the crazy

1,000 words • Created 4 Jan 2012 • Last modified 30 Mar 2013

In which I speculate wildly that inventing and administering psychotherapies is a little like learning and teaching programming languages.

What kind of personality test are you?

900 words • Created 27 Jun 2015 • Last modified 28 Aug 2016

This piece is perhaps history's only example of psychometric humor. Upon rejecting it from Perspectives on Psychological Science (in September 2016), the editor described it as "cute".


The perils of indirect language

300 words • Created 9 Sep 2009 • Last modified 2 Oct 2018

I protest indirect kinds of language, such as jargon, euphemism, and shorthand, especially in technical writing.

The perils of ridicule

800 words • Created 28 Aug 2013 • Last modified 24 Aug 2022

I argue that ridicule is a bad means of communication, whether you want to persuade or just inform. It only makes people angry.

Seriousness vs. formality vs. maturity

450 words • Created 17 Jul 2010 • Last modified 14 Aug 2012

I complain about the ambiguity of the terms "serious", "formal", and "mature" and the concepts to which they refer.

Data analysis

Guidelines for dataset design

2,000 words • Created 22 Aug 2016 • Last modified 19 Apr 2017

Some hints on how to design data-entry and data-storage systems for social science to make using the data as painless as possible.

Guidelines for asking data-analysis questions

250 words • Created 30 Jun 2016 • Last modified 20 Jul 2016

Please follow these few guidelines when asking a question about data analysis, whether on Cross Validated or elsewhere. These details may seem unnecessary, but providing them is likely to get you better, more complete, and more useful advice (partly by avoiding what's called the XY problem).

Reliability and predictive accuracy

200 words • Created 6 Jun 2014 • Last modified 7 Jun 2014

I show with an example that even in situations as simple as linear regression with two predictors, it's difficult to estimate (in advance of measuring the criterion) the consequences of unreliability for predictive accuracy.

XGBoost, missing values, and sparsity

450 words • Created 12 Sep 2018 • Last modified 18 Apr 2020

I use a simple example to describe how XGBoost handles missing data, and to demonstrate that sparse-matrix input can cause it to treat 0s as missing. (All code is in R.)


An introduction to chaos

3,000 words • Created 20 Nov 2010

A didactic essay on chaotic dynamical systems, with snazzy SVG diagrams. I wrote it for a topology class in my senior year of college.

Chaos in sequence spaces (PDF)

4,000 words • Created 8 Apr 2011 • Last modified 28 Apr 2011

My undergraduate thesis in mathematics. Unlike my undergraduate thesis in psychology (two theses? aye, such are the trials of a double major), it's not original research, just an explication of an existing paper. Here's the abstract:

I discuss a 2003 paper by Alfredo Peris, making it accessible to undergraduates with some knowledge of analysis and topology by providing background material and more detailed proofs. The main theorems identify chaotic families of functions on the sequence spaces c0 and ℓq. These functions can be expressed as a backward shift composed with an operator that applies a fixed complex-valued polynomial to each sequence element. The background material proves facts about c0 and ℓq and complex dynamics.

Miscellaneous nonfiction

Kodi's Top Three Tips for Academic Success

1,500 words • Created 26 May 2010

An attack on such bad habits of college students as note-taking and studying, with a few bonus jokes at the expense of Waldorf education. I intended the snarky tone of this piece to be humorous, not offensive. I did, however, seriously mean what I said here. Mostly.



600 words • Created Jan 2005 • Last modified 22 Jul 2005

In tenth-grade English, I was required to write a short story from a third-person limited perspective in which (a) the protagonist is in love with another character and (b) the feeling isn't mutual but (c) the protagonist thinks otherwise. Retelling the myth of Daphne seemed like a natural choice.

Wherein Faust eats green eggs in Hell

1,500 words • Created 10 Nov 2006 • Last modified 23 Nov 2006

The first part of Goethe's Faust, as retold by Dr. Seuss. I wrote and performed in this for a high-school course on Faust. The script turned out quite well considering that I can't scan.


1,500 words • Created 15 Nov 2020 • Last modified 13 Mar 2021

MatryoshkaNet is a lighthearted, unrealistic transhumanist setting. I made it up as an exercise in wish fulfillment: what kind of world would I want to live in? My biggest influences are probably Eclipse Phase, Star Trek, and the Culture.

The Antisexual Antiasceticism of Izydor Stolarz

2,500 words • Created 17 May 2021 • Last modified 19 Aug 2022

A short story in the style of Jorge Luis Borges, in which a fictionalized version of the author (yours truly, in this case) reviews the life and work of an imaginary iconoclastic writer.

The Bolzano–Weierstrass theorem

350 words • Created Dec 2009 • Last modified 5 Mar 2015

I once created an Uncyclopedia article on the Bolzano–Weierstrass theorem. In 2012, it was deleted for some reason. Here it is again. It remains my most elaborate attempt at mathematical humor.

The Lone Argonaut

200,000 words • Created 22 Dec 2008 • Last modified 16 Feb 2012

A fantasy novel I wrote as a teenager. It has its strengths and weaknesses, although it gets better over the course of the book, since it was my first (and only) novel and I took years to write it. It can be thought of as a response to His Dark Materials in a similar way that His Dark Materials is itself a response to The Chronicles of Narnia.

Antman vs. the Great Head

250 words • Created October 2001

I created this beautiful abomination, based on an in-joke, for a seventh-grade art class. I originally hand-wrote it on large-format paper. Here, I've transcribed the text, and I've used images for the drawings and magazine clippings.

How the Red-Bellied Piranha Came to Be

350 words • Created spring 1998

A creation myth I wrote for class in fourth grade. Aside from adding some paragraph breaks, I haven't edited it since.

Miss Information's Guide to Manners

200 words • Created 27 Sep 1999 • Last modified 9 Feb 2022

Some unserious etiquette advice in the whimsical style of the picture books What Do You Say, Dear? (1958) and What Do You Do, Dear? (1961), which were written by Sesyle Joslin and illustrated by Maurice Sendak.

Nine Princes in Amber, Abridged

6,000 words • Created 14 Aug 2021 • Last modified 3 Oct 2021

A parody of Roger Zelazny's first Amber book, Nine Princes in Amber (1970), in the style of a YouTube abridged series. An amnesiac man with a mysterious past finds himself thrust into the politics of a magically empowered group of siblings legendary in their immoderate lust for power and for each other.

This story also spoils later books in the first Amber pentalogy. Not so much the second, if only because I can't be bothered to read it. I have no plans to adapt any of them past Nine Princes.

You can also find this story on Archive of Our Own.

[See also my pony fanfiction.]