Extension (metaphysics)

Have you ever seen a piece of paper that has a certain length and width? Well, in the world of philosophy and metaphysics, we use the word "extension" to talk about things that have a length, width, and height. This includes things like your toy cars or the table you eat on.

Extension is a really important concept when we talk about substance, which is just a fancy word for all the stuff that exists in the world (like you, me, and the rest of the things around us). We say that matter (the stuff that things are made of) has extension, which means that it takes up space in the world.

Some people might think that extension is easy to understand because we can see it with our eyes. But here's the tricky part: when we talk about extension, we're not just talking about what things look like on the outside. Extension goes all the way through an object from one side to the other. Imagine if you cut your toy car in half – you'd see that it's not just a flat surface, but it has a thickness to it as well.

So, extension is just a fancy way of talking about how things are three-dimensional (meaning they have length, width, and height). We use this idea to describe not just what things look like, but how much space they take up in the real world.