This conversation is epic!

If I might add one other little snippet, everything external is a perception of the mind. A sensation like pain is caused by, say, an injury to the body that sends an electrical signal to the brain. The brain processes the data and the mind interprets that data is pain.

The funny thing is that, given practice, no external stimulus is actually necessary. During meditation, one can learn to develop a mind of love or compassion or whatnot. As A Red Panda said above, you start by thinking about people close to you, letting that love develop. After time, we learn what the emotion, that feeling is and the sensation that accompanies it (yep, there's an actual physical sensation there). Given enough time and practice, the meditator can bring up love or compassion or rejoicing without having to consider loved ones or something like that. No external stimulus needed. Want to feel compassion? Blip, there it is.

(I guess you could do that with pain, but why? Who would want to meditate on pain? Hmm ...)

But anyway, as everyone said, it's so intermingled it's tricky to try to separate them with language. Because they aren't actually separate, but all a perception of the mind.