Can you trust your internal moral sense?

I think so. I think that ultimately, that's all we have. Of course, we also have to think about things. But one's first reaction will be emotional. Yet sometimes it doesn't work. Here is a paragraph from William Saletan's article about William Hurlbut's proposal to sidestep the moral issues regarding stem cells by developing not-quite-human "biological artifacts." The paragraph describes how some members of the commission reacted to the proposal. (This is the article I discussed below in "Is it alright to create and destroy something almost human?".)

It's 'an attempt at a human that didn't go right,' Krauthammer ventures. 'I'm not sure we ought to want to reproduce that.' He alludes to an essay by council chairman Leon Kass: 'It could be what Leon calls sort of the wisdom of revulsion.' ('Repugnance,' Kass whispers, correcting him.) George says weirdness and repugnance aren't moral problems, but Krauthammer adds, 'Repugnant, weird, and somewhat human. If it's just repugnant and weird, it's just an aesthetic issue. If it's somewhat human, it's a moral issue.'

And here is an excerpt from Nicholas Kristof's Homegrown Osamas article from today's NY Times.

I interviewed Mr. Hale in 2002 because I had heard that he was becoming a key figure in America's hate community, recruiting followers with a savvy high-tech marketing machine. Over lunch in East Peoria, Ill., he described how as a schoolboy he had become a racist after seeing white girls kissing black boys.

'I felt nauseous,' he told me earnestly..

Another example: medical students famously become nauseous when first cutting into a human body. The lesson: even though disgust is apparently one of our basic built-in emotions (see, for example, Some notes on emotion, `east and west'), we can't always trust our emotional reactions.