MINUETTE: So, uh, what are you studying these days?
MOON DANCER: Science, magic, history, economics, pottery. Things like that.
MINUETTE: Yowza! You planning on being a professor or something?
MOON DANCER: No.
MINUETTE: So you're just ... studying!
MOON DANCER: Can I go now?
—My Little Pony: Friendship Is Magic, "Amending Fences"
However, this corresponds to a general pattern of causal relationships: observations on a common consequence of two independent causes tend to render those causes dependent, because information about one of the causes tends to make the other more or less likely, given that the consequence has occurred. This pattern is known as selection bias or Berkson's paradox in the statistical literature (Berkson 1946) and as the explaining away effect in artificial intelligence (Kim and Pearl 1983). For example, if the admission criteria to a certain graduate school call for either high grades as an undergraduate or special musical talents, then these two attributes will be found to be correlated (negatively) in the student population of that school, even if these attributes are uncorrelated in the population at large. Indeed, students with low grades are likely to be exceptionally gifted in music, which explains their admission to the graduate school.
—Judea Pearl, Causality
"It would be nice if implementation languages provided extensible string-indexable arrays as a built in type constructor, but with the exception of awk, Perl, and a few others, they don't. There are several ways to implement such a mechanism.
—Modern Compiler Design by Dick Grune, Henri E. Bal, Ceriel J. H. Jacobs, and Koen G. Langendoen (2000)
If, even as the price to be paid for a fifth vote, I ever joined an opinion for the Court that began: “The Constitution promises liberty to all within its reach, a liberty that includes certain specific rights that allow persons, within a lawful realm, to define and express their identity,” I would hide my head in a bag. The Supreme Court of the United States has descended from the disciplined legal reasoning of John Marshall and Joseph Story to the mystical aphorisms of the fortune cookie.
—Antoin Scalia; Obergefell v. Hodges dissent, footnote 22
PEARL: Oh, Steven. Humans just lead short, boring, insignificant lives, so they make up stories to feel like they're a part of something bigger. They want to blame all the world's problems on some single enemy they can fight, instead of a complex network of interrelated forces beyond anyone's control.
AMETHYST: It’s sad. And funny.
PEARL: Don't feel bad about it, okay?
—Steven Universe, "Keep Beach City Weird"
Education is a weapon whose effects depend on who holds it in his hands and at whom it is aimed.