If I make chicken soup for my friend when he's sick, and then I feel good because I can see I've made him happy, that's empathy. If I give $100 to a charity that helps someone I will never see, that's not empathy. The reward there isn't "I see someone happy and I feel their joy as my own." It's knowing abstractly that I've done the right thing. I've done both, and the emotional aspects have virtually nothing in common.
All forms of empathy must necessarily be indirect. When you see your friend happy, you don't directly percieve his happiness. Instead, you pick up on cues like facial expression and movements. You extract features that correspond to your mental model of human happiness. Let me make this clear and explain why it's relevant to the discussion.
Let's say your friend is asleep. You make him friend chicken soup, leave it on the table, and go to work. He later sends you a single text, "Thanks, the chicken soup made me really happy." This puts a smile on ...
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