Dear Diary, what is a table? You might say this is a very easy question. A table is a piece of furniture made of wood, it has 4 legs and a flat surface on top where you can place down objects. However there are many other possibilities. The table could be made of metal, glass or stone. It could have 3, 5, 2 or 264 legs. It could also be made of a solid block or the surface could float in the air with magnetism.
Well what about function then: If you can use it to place stuff down its a table. This also raises questions though. What if the surface isn't flat, but otherwise it looks like a normal table? Or if the table is made of a gaseous substance that things fall right through. There could be just a thin metal frame around a big open hole where the surface usually it and we would still see it as a table. Kind of like how these surrealist teacups with fur on them cant be used to drink tea but we still identify them as teacups.
On the other hand there are objects we usually don't identify as tables that can be used just like a table. A card board box for example or a chair can be used splendidly to place things on. Same goes for a bed, a car or a barrel of toxic waste.
And when exactly does the matter that a normal table consist of become a table. The wood spent long years as a tree before it was turned into a table. So at what point in the process did it turn table like? When it was cut down, while it was worked on or only when it was finished?
It seems like the way we think of tables isnt completely determined by the physical characteristics at all, but rather by what Plato called ideas. Objects of the mind that can be linked to physical objects. We use ideas to understand the world around us. This is a table, because I think it is and therefore I use it as a table. To me it is connected to the idea of the table.
So despite there seemingly being an objective reality, our perspective on that reality matters a lot. It changes how we interact with the world. I could use my chair as a table if my perspective changed on it. After all it has 4 legs and a flat surface. If I chop down the back its exactly the same thing. So the more flexible our perspective on the world is the more we can see past the definitions that are really just made by people. And these definitions change all the time. What people called a clock 100 years ago has little in common with what we use today to tell the time. The clock has become completely digital, the gears that have once defined it have become irrelevant. Its just pixels on a screen now.
Another thing we could use as a table is a person. The person could go down on their knees on all fours. It would have 4 legs and a flat surface and clearly the person is doing this so we can use them as a table. And the amazing thing about a person is that we can ask them what they think they are and if its ok to see them as a table. And if they say they are a table I would not doubt them and put my glass on their back. Because they have attached the idea of the table to themselves and really that is all that defines a table.