School subjects do harm to educators' power to reason. Here's what I mean by that: imagine a school stops teaching history. There's just no class called "history" anymore. Let me guess what you're thinking about this school: its students will be intellectually malnourished. Depending on your ideological predilection, here are a few worries you might have:"they'll grow up unmoored from their heritage", "they won't learn from the mistakes of the past (for example, how can you understand the potential implications of this political moment without knowing about Germany in the 1930s? And how can you understand Black Lives Matter if you don't know about the Civil Rights movement?)", "without turning a critical lens on the stories we tell ourselves about the past, students won't be able to understand the power structures that undergird all contemporary discourse."
OK, I share all these concerns. But here's a thought experiment: let's say that in every school across the United States, all students took a class called Philosophy. In it, students learned about the fundamental principles of argument, and the various attempts across the millenia to create a coherent theory of justice, of judging right and wrong, and (more recently) of fundamental rights. They learned the mechanics of argument and logic. Now imagine that the schools decide to stop teaching philosophy, an replace it with history. Wouldn't that seem like a catastrophic loss to these fictional educators?
One explanation for our attachment to our current slate of school subjects is what behavior economists call the "endowment effect", by which people tend to overvalue what they own ("overvalue" in the sense that people tend to want more money for things they already own than other people are willing to pay).
In the case of school subjects, we fear what we would lose by getting rid of a subject. But this fear implies something totally inaccurate: it implies that there is a really good reason that we teach the set of subjects that we teach. But if you consider the skills and knowledge that you need as an adult right now (let alone what we might need in the future) it's obvious that English, History, Pure Math, Physics, Biology, and Chemistry are an odd set of categories to build an education around. And I'm not making an instrumentalist "we should be educating people for the careers of today" argument here. Rather, I think this is a weird list of subjects for ANY POSSIBLE desired educational outcome. The only outcome it fulfills is "to become an educated person according to the current definition" and arguing for the current list of subjects on that basis is (as we'd all know if we'd taken philosophy in school) circular reasoning.
Here's what I think: subjects are a weird way to organize school. If we were creating the concept of "school" now, there's no way we would use them as an organizing principle, because they aren't a good way to organize learning. They are, in fact, a "folder" system, and what we need is a "tag" system.
The "folder" system was, until recently, the only way to organize information: when I was growing up, information was mostly stored on paper, and sorted in folders. Because organizational structures tend to outlive their usefulness (sound familiar?), most computers still use folders to organize information.
This is not optimal - documents do not have only one characteristic and if I'm trying to file an interesting article that argues that you can learn a lot about the 2016 presidential election by studying the fight over Title Nine in universities, what folder should it go in? "Political Analysis?" "Current Events?" "Women's Rights?" "Sports?" "Higher Education?" "Argumentative Writing?" It depends on what I want to use it for - and what I want to use it for will vary from semester to semester.
Because of this, computers increasingly (though not as quickly as I would like) organize files by tagging rather than by folders. That article about Title 9 can only go into one folder, but I can give it as many tags as I want.
Education should have a tagging system. If students are learning through interdisciplinary projects, it's easy to identify what they are and aren't learning in each project - which means it would be easy to give it "tags". Over the course of the year, these tags would make it easy to see what skills and information a student had been taught, and what they hadn't (and if these tags connected to assessment - for example through portfolios and Presentations of Learning, you'd be able to see what the student had actually LEARNED which is a lot more important than what they've been "taught").
So let's ditch "subjects" as an organizing principle - they make us think in terms of what's taught rather than what's learned, and they reinforce the endowment effect in totally unhelpful ways.
For more on "subjects", check out "Changing the Subject" by Larry Rosenstock and Rob Riordan, which Andrew Gloag turned into an animation narrated by Larry.