Is telepathy possible?
I have never had a telepathic experience and nor have I met anyone who claims to have had one. I think I would be pretty sceptical if I did.
But is it even possible to have a telepathic experience? How would you know you weren't the victim of some kind of psychosis? How would you be able to sort out the 'ownership' of thoughts and other mental states?
When I think about telepathy I imagine it as some kind of telephony without the instruments and wires. Let's say I wanted to communicate with my friend Sandra. With a telephone I pick up the instrument, dial Sandra's number, hear some rings and clicks and then I hear Sandra saying 'Hello' (or whatever). I know it's Sandra because I recognise her voice. I know it wasn't me saying 'Hello' because I didn't open my mouth.
But with telepathy all the physical actions and events seem to be eliminated. If I want to communicate with Sandra I presumably 'tune in' to her brain somehow. But then all sorts of problems start. How do I know I've really got Sandra's brain, and not somebody else's? Perhaps there is some unique quality of Sandra's mental states that immediately identify them as hers, analogous to the unique sound of her voice, but it's hard to know quite what this quality could be. When I 'hear' 'Hello' it will not have been produced by her vocal chords. If I became aware of a sudden yearning for pizza, would it me that was yearning for pizza, or Sandra? How would I be able to distinguish our yearnings? How would I know the 'voice' that I was 'hearing' was not a delusion, a case for psychiatric treatment?
All these considerations lead me to think that the notion of telepathy is hopelessly problematic and can be ruled out a priori.
But then supposing there is an advance in wireless telephony in the future. Instead of carrying portable handsets we will all have chips implanted in our brains. These chips will be wired up to the brain in such a way that if I want to dial, for example, Sandra's number, I just have to think of her number. Sandra's chip will then start 'ringing' in her brain (only she will hear it) and we can proceed to have our conversation merely by 'thinking' our words, rather than physically producing them as speech. This might seem far-fetched, but not beyond the realms of logical possibility.
So one intuition is pulling me one way, and the other intuition is pulling me the other. Which intuition is better? Can they be resolved?