Hume wrote about how perceived similarity is a factor of empathy, for example, a human cannot relate to a piece of string.

The piece of string.

@selzero Human empathy extends to all things, literally things. We strap knives to roombas and collect little rocks and call them friends.
I don't hang around folks who don't have at least a little sympathy or empathy for things and other living beings.
We all break under constant stress, just like the string. I feel for it