如何理解休谟、斯密等人的“同情（sympathy）”

The minds of men are mirrors to one another, not only
because •they reflect each others’ emotions but also because
•those rays of passions, sentiments and opinions can often
reverberate and gradually fade away. [Hume is likening •the
workings of sympathy with •the effect on a ray of light of a facing pair
of mirrors that bounce the light back and forth between them; the
‘gradually-fade-away’ feature is special to sympathy, and doesn’t carry
over to the mirrors.]
Thus the pleasure that a rich man receives
from his possessions is thrown onto the onlooker, in whom
it causes pleasure and respect; these feelings are perceived
and sympathized with by the rich man, thus increasing his
pleasure; and this, being reflected back yet again, becomes a
new basis for pleasure and respect in the onlooker. The basic
satisfaction in riches comes from their power to enable one to
enjoy all the pleasures of life; and this, being the very nature
and essence of riches, must be the primary source of all the
passions that arise from riches. Of these resultant passions,
one of the most considerable is the love or respect that
others have, which has to come from their sympathy with
the pleasure of the possessor. But he also has a secondary
satisfaction in riches, arising from the love and respect that
come to him because of them; and this satisfaction is simply
a second reflection of that basic pleasure that came from
himself. This secondary satisfaction or vanity becomes one
of the main advantages in being rich, and is the chief reason
why we either want to be rich ourselves or respect riches in
others. This, then, is a third rebound of the original pleasure.
After that it’s hard to distinguish images from reflections of
them, ·and thus hard to go on counting ‘rebounds’·, because
of their faintness and confusion.
Treatise II 5: David Hume ii: Love and hatred