Fans of the Judge John Hodgman podcast know that the harder you interrogate the category "sandwich," the less definitive it becomes, until you find yourself raging over tacos and hot-dogs.
Inspired by an argumentative, difficult student, Dr. M. Ritchey uses a dialog about sandwiches to teach her university philosophy students about the Socratic method, apparently with great success:
— Well, Socrates, I am happy to tell you what a sandwich is, as I have great knowledge of these things as you know.
— Thank you, Euthyphro, I will be glad to listen to you, for you are a learned man and I am just a poor beggar. So tell me, please, how can we know that which is a sandwich, apart from those things that are not sandwiches?
— Socrates, it could not be more simple. A sandwich is anything edible held in a container that is also edible.
— I see; that is very clear indeed. So this taco is a sandwich.
— No Socrates, that is a taco. A sandwich is something quite different, as you may quickly see by noting that they are called by different names.
— And yet, Euthyphro, here we have some soy ground beef—surely this is edible—and as you see, it is held in this container, which is a fried tortilla, and which I eat along with the material inside. Surely this is a sandwich!
— Well, Socrates, that is not quite right. I will try to be more clear: a sandwich is that which is edible, held in a container made of bread, surely.
— So then this hot dog, of course, is a sandwich. Thank you, Euthyphro!
— Well Socrates… a hot dog is something very like a sandwich, and yet it does not seem to me to be exactly a sandwich either, somehow. I see where you have misunderstood—let me clarify. A sandwich consists of some edible material, in between TWO pieces of bread, which must be separate from one another.
— I see; that is very clear indeed. So this pizza placed face down atop this other pizza, this is a sandwich.
— No, Socrates, I see that you do not understand at all. That is nothing like a sandwich.
— Now Euthyphro, how can this be? For truly here I see edible items—those are cheese, tomato sauce, and vegan pepperoni—and they are indeed to be found in between two pieces of bread—that is the pizza crust. How can this not be a sandwich, then?
Is This a Sandwich? [Dr. M. Ritchey, PhD/Medium]
(via Metafilter)
(Image: Taco icon, Sue Hong and Omar Lechuga, CC-BY-SA)