of headaches and mindtwists
A friend mentioned today that she has been suffering from migraines for the past couple days. Somewhat idly, she noted that she can’t tell if the headache she has today is in fact the same headache as the one that gripped her yesterday. Today’s pain was clearly of a similar type, but apparently less intense. But was it the same headache?
This question turns out not idle at all. Suppose you have a painful headache on Monday and fall asleep anyway. Then you wake on Tuesday morning experiencing pain that feels (so far as you can tell) exactly like the pain you felt the previous night. Are you thereby experiencing the same headache as the one on Monday, or a similar yet distinct Tuesday headache?
There are considerations on both sides. Here’s a good reason to think it’s the same headache: it feels the same, with the same intensity. The Monday pain and Tuesday pain are tightly linked chronologically. It’s plausible to think that the neuronal instantiation of the pain is the same on both days.
But, on the other hand: where is the headache while you sleep through Monday night? You don’t feel the headache then. Does it go away and come back? Where does it go? If the neuronal instantiation is maintained through the night, does it make sense to call that the instantiation of a pain if you in fact aren’t feeling anything at the time? But if the neuronal instantiation is interrupted during the night, then isn’t it reasonable to call the new instantiation on Tuesday morning a distinct headache? (Consider: the neuronal instantiation of my visual experience of the ceiling of my apartment on Monday morning might, in principle, be the same as the neuronal instantiation of my visual experience of the ceiling on Tuesday morning - but we’re inclined to regard these as distinct experiences.)
I don’t have an easy answer here. I just want to notice that this sliver of a question ties right into some much bigger issues. If your pain’s absence overnight gives us reason to question the identity of the Monday pain and Tuesday pain, what conclusion should we draw about you? You’re not conscious all night long - you have periods of dreamless sleep. What, exactly, entitles us to say that you are the same person on Tuesday as on Monday, given that no uninterrupted chain of experience connects those two subjects?
These are, of course, familiar problems for philosophers, and I’m aware of the unfathomable depths of literature lapping these conceptual shores. But this is a blog post, not a journal article, so I’m not going to cite or discuss anything. For now, I’m content just to reflect on how quickly a simple question about a painful headache can give rise to something much less simple - but hopefully not as painful.
image via healthmattersatwork.com