One question I like to ask in response to questions like this is “what do you plan on doing with this information?” I’ve generally found that thinking consequentially is a good way to focus questions.
In case the answer to Qiaochu_Yuan’s question is something like “I’m trying to establish the moral status of tickling in my provisional moral system”, note that IIUC the sensation felt when eating spicy foods is also pain according to most definitions, but a moral system according to which eating spicy foods is bad can go #$%& itself for all that I’m concerned.
Is tickling a type of pain?
Dissolve the question.
One question I like to ask in response to questions like this is “what do you plan on doing with this information?” I’ve generally found that thinking consequentially is a good way to focus questions.
The simplest way of categorizing this would be based on the biology of which nerves nerves are involved. It appears that the tickle sensation involves signals from nerve fibres associated with both pain and touch. So… “Kind of”.
In case the answer to Qiaochu_Yuan’s question is something like “I’m trying to establish the moral status of tickling in my provisional moral system”, note that IIUC the sensation felt when eating spicy foods is also pain according to most definitions, but a moral system according to which eating spicy foods is bad can go #$%& itself for all that I’m concerned.