A demi-vegetarian is a person who eats little meat and is conscious about where they get it, trying to minimize the suffering of animals. Peter Singer calls it Compassionate Omnivorism. I think thats a mouthful, so I like to call it demi-vegetarianism like R.M. Hare. I was a demi-vegetarian for about 4 years before I converted to being a full vegetarian (with the exception of gelatin.... man you just can't get away from that stuff).
Michael Pollan really turned me into a vegetarian, contrary to his own thesis. In the Omnivore's Dilemma he goes out of his way to show us that there are humanely treated animals. I don't disagree. However, he points out that the industrial organic machine of Whole Foods isn't much better in terms of animal treatment. I agree.
So our alternative is to find the humanely treated meat.... But how exactly do we do that? Its rather impractical (at least for me) to research all of our food options to discover the treatment of the animals. The farm that Pollan features in his book, he also points out will not ship any of their meat. So if I want the idyllic farm setting that Pollan describes in his book, I think I have to go to Pensylvania to get it, which is impractical for me, considering I'm in California. The alternative was of course humanely treated meat. Whole Foods might be a place where the typical demi-vegetarian would shop. But Pollan's description of the industrial organic machine wasn't much better than the standard factory farm. Sure things would be organic, but organic doesn't equate to humane, and when producing food at the scale that Whole Foods demands, its difficult to imagine that the food would indeed be truly humane.
It forced me from considering my self a compassionate omnivore, to what I really was, a-hope-and-faith-in-the-compassion-of-people-who-are-saying-they-are-compassionate-to-their-animals-and then-trying-to-turn-a-profit omnivore.
Consider the analogy of clothing. If you were vehemently against sweatshop labor, and you found a label that said that it was not made in a sweatshop, and bought it on faith that it was not from a sweatshop, even though it was in fact from a sweatshop. Would you be any better than the person who was not conscious of buying their clothes from a sweatshop? Maybe in terms of character you would be... But good characters want to ACTUALLY do good things, not seemingly good things.
Peter Singer spoke at Stanford last year about compassionate omnivorism, advocating it. I asked him how it we could actually get that kind of meat, and he replied that it was simply readily available*. I don't buy it. It strikes me as being naively trusting in a network of suppliers that have never earned my trust, and have been shown time and time again that they don't deserve our trust.
There can't be a middle ground on this until the meat industry is willing to make food production transparent. Only then can we really be assured that the animals we're eating are humanely treated, and a middle ground, demi-vegetarianism, becomes reasonable. Until then, the argument for demi-vegetarianism is a good one, but not one that is practicable by the majority of people.
*I'm simplifying my question and his response for the sake of brevity here.