(I've got a migraine and news consumption has been low so I thought I'd shoot this out there)
Vegetarianism. The principle (as I understand it from friends who choose this way of life) is that it is wrong to eat animals, whether because of moral grounds, theological grounds, tastes or some other idiopathic reason. Herbivorism if you please, which, as referred to in the Wikipedia link, is the consumption of plant substances.
I adore plant substances, but I am also quite a fan of meat. However, I am not such a fan as to become a carnivore.
Things that irk me about Vegetarians is their obscure and often hypocritical principles.
You will often find vegetarians who wear leather without a second thought, although it is not currently vogue to wear fur. They are generally lucky enough to get substitute jackets but shoes still tend to contain leather.
Therefore I find fault with their principles. I am a great admirer of those with the tenacity to pursue nothing but man-made substances. But as the cruelty of eating other live animals is the core reason for the majority of vegetarians, stop being so bloody hypocritical!
Don't even get me on to Pescatarians.
I'm quite principled. And I'm liberal enough to accept what people do, but I will be inclined to moan about hypocrites.
My own approach to eating meat is a principled one, I believe.
I eat animals where humans make use of the majority of the materials the animal produces in death. For example, a cow produces leather as well as meat, the internal organs are also consumed with offal feeding pets. Therefore eating cows is justified. As are pigs and sheep. But eating game is not. The majority of game meat is wasted, as are skins and internal organs.
It works both ways too. I wouldnt wear mink because we dont consume mink meat. I wear leather, and suede but not rabbit fur.
On a different note, I am vaguely amused by my vegetarian friend who seeks to eat meat at festivals on the basis if it can kill you as meat, it is still an animal.