Since the beginning of time, philosophers have debated the questions that define us as humans: Where did our universe come from? What is the meaning of life? Is a hot dog a sandwich?

We’re still trying to answer the first two, but we can definitively answer the third question.

A hot dog is not a sandwich.

A hot dog is a taco.

Let me explain.

Whether a hot dog is a sandwich is a problem that has long divided people who like to get into meaningless arguments on the Internet. Some say that a sandwich is anything in between bread, which would make a hot dog a sandwich. But some say bread that is not in two distinct slices is different — and that tubular meat within it deserves its own distinct category. The National Hot Dog and Sausage Council does not call a hot dog a sandwich: “Limiting the hot dog’s significance by saying it’s ‘just a sandwich’ is like calling the Dalai Lama ‘just a guy,’ ” says its website. But the Merriam-Webster dictionary disagreesNew York and California tax law say a hot dog is a sandwich. And Supreme Court justice Ruth Bader Ginsburg, when asked by comedian Stephen Colbert, issued this ruling:

Ginsburg: You’re asking me? Well, you tell me what a sandwich is, and then I’ll tell you if a hot dog is a sandwich.

Colbert: A sandwich is two pieces of bread with almost any type of filling in between, as long as it’s not more bread.

Ginsburg: You say two pieces of bread. Does that include a roll that’s cut open but still not completely?

Colbert: That’s the crux. You’ve gotten [it] immediately. See, this is why you’re on the Supreme Court. That gets immediately to the question: Does the roll need to be separated into two parts? Because a sub sandwich — a sub is not split, and yet it is a sandwich.

Ginsburg: Yes.

Colbert: So then a hot dog is a sandwich?

Ginsburg: On your definition, yes, it is.

I am sorry to report that this decision is incorrect. Everyone who has been approaching the hot dog vs. sandwich problem has been looking at it all wrong. It is not a question about bread and the unique nature of cylindrical beef. It is a geometry problem.

Enter the Cube Rule, a simple way to categorize What Foods Are and What Foods Aren’t. According to the Cube Rule, there are eight categories of food, each defined by the placement of starch. Use a cube as your guideline for where the bread or starch goes, and it will determine what a food truly is — and whether it is a sandwich. Starch only on the bottom? It’s a toast. Starch on the top and bottom that is not connected is, obviously, a sandwich. But starch on the bottom and two opposing sides is a taco. Therefore, a hot dog is a taco. And, to correct RBG, a sub is also a taco. Rolled starch on the top, bottom and two opposing sides is, according to the Cube Rule, maki roll sushi. Therefore, an enchilada is sushi. Starch on every side except the top, like a quiche, is a bread bowl. Any food fully enclosed in starch is a calzone. A corn dog is a calzone. A Pop-Tart is a calzone. A bean pupusa is a calzone.

The handy diagram below, created by Twitter user @Phosphatide, makes it easy to understand the Cube Rule and issue decrees on other dishes. He drew it after the hot dog debate came up on a video game stream he was watching, and another user outlined the basis of the Cube Rule. His name is Brandon, but the 25-year-old student declined to give his last name because he didn’t want to be seen as taking credit for the theory, even though the diagram and many of the clarifications and rulings on particular food items are his.

“I like the idea of having clarity in how we talk about food,” Brandon told The Post. “I would be very amused to see the Cube Rule start taking off.”

The Cube Rule of food, courtesy of Twitter user @Phosphatide

So what about starches that don’t have “sides,” like spaghetti? Simple answer: All starches that do not hold a defined shape, or foods that do not contain starches, are salads. Poutine is a salad. Fried rice is a salad. Mashed potatoes are a salad. A steak is a salad, albeit one with only one ingredient. Any starches or non-starches suspended in liquids are soups, which are just wet salads. A vanilla soy latte is technically, according to the Cube Rule, a three-bean soup. And while a loaf of bread, the building block of this formula, might be a six-sided starch, it is not a calzone: it is merely an uncut toast. This applies to any breads that do not have a filling. A plain doughnut is a toast, but a jelly doughnut is a calzone. A dinner roll is a toast.

As the illustrator of the Cube Rule, Brandon is also its arbiter of disputes. Ask him about any food, and he will issue a ruling.

Let’s start with an easy one: pizza. “It’s just a toast,” he says. “It’s a large piece of bread.” A cherry pie is a bread bowl if it has an open top, but it’s a calzone if it has a closed top.

For the latter, “If you were to serve it as a slice, it would be a taco, because it has three sides, technically,” Brandon said. “That’s what brought this whole thing together as mostly a joke. That was my favorite example.”

A burrito is a trickier food to consider. “That would be a topic of debate — it’s created with a single tortilla roll, by nature it feels like more of a four-sided object,” he said. “I would be willing to consider it as a calzone, as well.” Interestingly, the sandwich chain Panera tried to argue in Massachusetts court that a burrito is a sandwich — they felt that the addition of a Qdoba to a mall shopping court violated a contract that said they were to be the only sandwich chain in the space — but the judge disagreed, ruling the burrito not a sandwich in 2006. Nevertheless, the USDA’s Food Standards and Labeling Policy Book describes a burrito as “a Mexican style sandwich-like product.” Wrong.

A piece of fried chicken, if it has a nice, crunchy breading on it, would technically be a calzone. A shepherd’s pie or a chicken pot pie, with crust only at the top, is another difficult categorization. “By the nature of the starch location, I would also rule them as toasts with the ‘jam side down,’ ” Brandon said.

After Brandon posted his illustration, thousands of people chimed in with other applications of the Cube Rule. Nigiri sushi, with the starch at the bottom, is a type of toast, one user pointed out. A Twinkie is a calzone, and a Swiss Roll is sushi. Pigs in a blanket are sushi. Some posited that a multi-decker sandwich is an additional category — a cake — which makes lasagna a meat-and-cheese cake.

How seriously you decide to take any of this is up to you. But it is very amusing to look at, say, a piece of Gushers candy and declare it a calzone or to call a meatloaf a salad. Because, yes, for the record: It is a salad of meat and vegetables and bread crumbs that has been cooked. Unless you make it an open-faced meatloaf sandwich. Then, it’s actually a toast.

More from Voraciously

Sour Patch Kids cereal spoils a perfectly good bowl of milk