We are constituted so that simple acts of kindness, such as giving to charity or expressing gratitude, have a positive effect on our long-term moods. The key to the happy life, it seems, is the good life: a life with sustained relationships, challenging work, and connections to community.
Empathy has some unfortunate features - it is parochial, narrow-minded, and innumerate. We're often at our best when we're smart enough not to rely on it.
The irrationality of disgust suggests it is unreliable as a source of moral insight. There may be good arguments against gay marriage, partial-birth abortions and human cloning, but the fact that some people find such acts to be disgusting should carry no weight.
Some of the natural world is appealing, some of it is terrifying, and some of it grosses us out. Modern people don't want to be dropped naked into a swamp. We want to tour Yosemite with our water bottles and G.P.S. devices. The natural world is a source of happiness and fulfillment, but only when prescribed in the right doses.
Maybe one of the most heartening findings from the psychology of pleasure is there's more to looking good than your physical appearance. If you like somebody, they look better to you. This is why spouses in happy marriages tend to think that their husband or wife looks much better than anyone else thinks that they do.
You'd expect, as good Darwinian creatures, we would evolve to be fascinated with how the world really is, and we would use language to convey real-world information, we'd be obsessed with knowing the way things are, and we would entirely reject stories that aren't true. They're useless. But that's not the way we work.