> Buddhism claims that our feeling of separation (and thus the multiplicity of subjective experiences) is an illusion. But I never really understood why.

They've made a good book to help people get the concept. It's called "the gateless gate" and it's a series of seemingly non-sensical stories, that you're supposed to think about and try to see the meaning behind it.

If you want to give the exercise a try, it's on wikisource: https://en.wikisource.org/wiki/The_Gateless_Gate

For an intro. I think the old stories have too many anachronisms for modern readers. There are too many meanings in the phrasing that the readers of the time would already know.

Do you know of any modern translations that frame the story in actual modern references?

I think it would make a bad introduction to buddhist philosophy in any way, it's meant as a more "advanced" text imo. Starting with a plain english intro (like Alan Watts, The Way of Zen) or simpler texts (the Dhammapada) should be easier.

VS Ramachandran has an interesting talk about mirror neurons, which is a subset of motor neurons. They activate when you perceive anybody else doing something as opposed to only activating during your actions. This is fundamentally a built-in empathy/group learning mechanism, but it also has some other interesting implications too.

For example, when somebody touches someones hand in your view, your mirror neurons activate just like you yourself have been touched. Then your nerve endings in your hand send a signal to cancel the effect, but sometimes you still get a tingling from the neural confusion depending on the strength of the signal (e.g. watching someone getting kicked in the balls or russian daredevils walking on top of highrises). But, if there is no nerve endings there, there is nothing to cancel the signal, so you do experience another persons feeling of being touched as your own. Therefore, the only thing that separates our consciousness is literally our skin and our nerve endings on it.

I sometimes wonder if we are all basically the same conscious, threading through all of the "antennae" of life one after another. But I find this idea painful because it is tantamount to an immense cosmic loneliness.

Like in "The Egg"?

Yes, although The Egg ultimately presumes separation of consciousness at some "higher level" given that there is a dialogue between such consciousnesses. My greater sense of loneliness comes from a sense that the very premise of a separation of consciousness exists as a deliberate goal of our universe, which was made by a "God" who is actually all of us, as a means to keep myself/ourself company and to introduce love. Sort of like we are all branches of the same tree. But people talk about having epiphanies about this as if it is a good thing that we are all the same, leading to a connectedness. But it also leads to loneliness.

Sorry for the dump.

Loneliness is a human instinct based on our evolutionary history as social primates though - if you travel up the antennae enough that there's no 'others' there's also no evolutionary pressures to make that loneliness a source of danger.

But what I find cool is that the lonely social ape can also look up the antenna and find all the security it could want - where I think some religions err is that when this happens, if you keep identifying with the insecure social ape rather than the many-antannaed-deiform it can interfere with the smooth communication between the two.