[cjg]

I don't think arguing about definitions is pointless, although it often turns out that way.

Take, for example, the classic "if a tree falls in a forest and no-one is around to hear it, does it make a sound?". Resolving this question comes down to seeing that it depends on how sound is defined: pressure waves in the air or a neural state change related to those waves hitting an ear.

Once we see that a words (like "sound") has several definitions it allows us to see the world more clearly. Perhaps we invent new words for the sub-concepts that are generated.

[arrrg]

That tree example perfectly illustrates why arguing about definitions is pointless. There is no reason at all to ever really disagree about definitions (except maybe for convenience).

However you define sound, the material facts of the situation are unchanged. You do not change anything in reality by defining it differently, you are merely changing something in your brain, i.e. how sound is represented inside it. That is also why the tree question is anything but deep. It’s extremely straightforward, there is no mystery, it’s only our brains screwing up (in the way it represents things).

Therefore, if it seems like some word is differently defined by different people all that has to be done is that everyone has to make clear what their definition is, that’s all. There is no point arguing about it, there isn’t even much point in trying to come to an agreement (except convenience).

If everyone know everyone else’s definition of something it’s perfectly possible to talk about it, even if all individual definitions are contradictory, it would just be hard to keep track of everything.