How? What's the method? How do you tell if a person is experiencing type A or type B fun? I'm not asking rhetorically. Are there multiple types of happiness? Multiple types of anger? How do you determine when a thing has "multiple types" and when it doesn't?

I've always assumed that if I can observe multiple instances of a thing and tell that they are different, they are – in fact – different. Maybe I am too much an essentialist there, but it seems to me that if you are going to start doubting the evidence of your ability to differentiate emotional reactions, you have a lot bigger problem than trying to determine what is fun.

And, yes, I am both being snarky and communicating what I intend.

If you want to keep going down that road of questioning, you have essentially decided that communication is impossible. If we cannot accept, axiomaticly, that someone else who is reporting their perceptual difference in the world is not reporting something which is evidential, talking is done. If your position requires that you question all sensory input and all interpretations thereof, including your own, why does anyone need to talk to you?

Again, both snarky and truthful. Philosophy is fun, but at some point you have to shift to engineering if you care about achieving anything.

I don't follow this argument at all. There's room in the food industry for lots of sweet-tasting things, even though sweetness seems to be a pretty basic sensation whose mechanisms can be studied.

And yet, you would be wrong. While "sweetness" is a pretty basic sensation, we have scientific research which differentiates types, kinds, and intensities of "sweetness," with multiple mechanisms, in fact. Not all sweetness is the same, and not all sweetness comes from the same places, and not all sweetness is experienced the same way, which for someone who is trying to engineer food has a differentiatable set of experiences with a multitude of means to achieve different kinds.

And this all loops around to my original example: cancer. If you are a doctor and trying to treat a cancerous growth, it does you no good to say "well, this is cancer." What kind of cancer? How does that kind of cancer respond to different stimuli? How likely is it to kill the patient? How soon? If ever? Sure, you can say "you got cancer," but when you can plainly differentiate based on a multitude of traits and mechanisms – you'd be an idiot to try to work with those traits and mechanisms while simultaneously denying that they can be detected.

So, yes – I suppose we could sit down and try to draw up a temporary, rough, quantified and qualified architecture of types of fun, but it would be ridiculous to suggest that they don't exist and frankly I don't have time to do that sort of thing – I have games to build, games to run, people to entertain.

We know that it's different. We can see it. If we want to formalize it, that's one thing – but if we want to use it, a formalization is certainly not necessary. We do have to recognize the possibility of differentiation, however.