Dear K2PK,
This is an excellent question. I believe that certain Muslims living in the West need to legitimize certain behaviour which may be deemed un-Islamic and do so by "inventing" their own brand of Islam. In my opinion, Muslims are permitted to eat meat which is slaughtered in the name of God (specifically the mono-theistic God).
"He hath forbidden you only carrion, and blood, and swineflesh, and that which hath been immolated to (the name of) any other than Allah." (2:173)
Here it is clear what is forbidden - carrion (or already dead meat), swineflesh (pig), and meat which is not killed in the name of "God" (this would eliminate all meats slaughtered strictly for profit without the recitation of the name of God during slaughter).
"But he who is driven by necessity, neither craving nor transgressing, it is no sin for him. Lo! Allah is Forgiving, Merciful." (QS. 2:173)
Here it is indicated that you may eat meat, which is not slaughtered in the name of Allah, if "driven by necessity". Some living in the West argue that because accessibility to Halal or Kosher (Jewish) meat shops is limited they are forced to eat un-Halal meats. This of course is up to an individual's judgment - who is "driven to necessity" or not? Personally I believe that access to Halal meat in the West has grown substantially, and legitimizing these practices by citing this verse is very weak.
1) This verse provides some specific guidelines for lawful and unlawful, (notice the significant emphasis on the humane treatment of animals and criticism of brutatlity towards living things):
"Forbidden unto you (for food) are carrion and blood and swineflesh, and that which hath been dedicated unto any other than Allah, and the strangled, and the dead through beating, and the dead through falling from a height, and that which hath been killed by (the goring of) horns, and the devoured of wild beasts, saving that which ye make lawful (by the death-stroke), and that which hath been immolated unto idols. And (forbidden is it) that ye swear by the divining arrows. This is an abomination. This day are those who disbelieve in despair of (ever harming) your religion; so fear them not, fear Me! This day have I perfected your religion for you and completed My favour unto you, and have chosen for you as religion al-Islam. Whoso is forced by hunger, not by will, to sin: (for him) lo! Allah is Forgiving, Merciful." (QS. 5:3)
2) Here the food of the "People of the Book" is made lawful to Muslims (read note below verse):
"This day are (all) good things made lawful for you. The food of those who have received the Scripture is lawful for you, and your food is lawful for them." (QS. 5:5)
Note: Today Jewish kosher meat is slaugtered in the name of God. In my opinion the meat of Christians is no longer lawful to Muslims, unless it is killed in the name of God (which it no longer is) - and this view is quite clear from the verses below.
3) More warnings to eat meat slaughtered only with Allah's name:
"Eat of that over which the name of Allah hath been mentioned, if ye are believers in His revelations. (QS. 6:118)
"How should ye not eat of that over which the name of Allah hath been mentioned, when He hath explained unto you that which is forbidden unto you unless ye are compelled thereto. But lo! many are led astray by their own lusts through ignorance. Lo! thy Lord, He is Best Aware of the transgressors." (QS. 6:119)
"And eat not of that whereon Allah's name hath not been mentioned, for lo! it is abomination. Lo! the devils do inspire their minions to dispute with you. But if ye obey them, ye will be in truth idolaters." (QS. 6:121)
"He hath forbidden for you only carrion and blood and swineflesh and that which hath been immolated in the name of any other than Allah; but he who is driven thereto, neither craving nor transgressing, lo! then Allah is Forgiving, Merciful." (QS. 16:115)
"And speak not, concerning that which your own tongues qualify (as clean or unclean), the falsehood: "This is lawful, and this is forbidden," so that ye invent a lie against Allah. Lo! those who invent a lie against Allah will not succeed." (QS. 16:116)
It is evident from these verses that meat lawful to Muslims must be slaughtered in the name of God. There is a tremendous amount of Fiqh on this subject, regarding the method of slaughter and the technical aspects, which I am not aware of.
In terms of reasonings behind this requirement: It is my opinion that Islam, by requiring this method of slaughter, has:
1) Demonstrated the sanctity of life. Animals are living beings and their life to is precious. Humans can consume animals, only when they slaughter them with respect and with reverence to the Creator. In Islam hunting for sport is forbidden - "killing for fun and sport" is not lawful. Animals can only be slaughtered for a source of food and sustenance. And furthermore - they should not be slaughtered or consumed in excess - for as the Quran states "Eat of the good things We have provided for your sustenace, but commit no excess therein, lest My Wrath should justly descend on you: and those on whom descends My Wrath do perish indeed." (20:81) The "excess" with which meat is consumed in the west is quite disgusting.
2)Islam has graced animals and living things with a telos (a reason for being and existing). Animals are not solely created for the purpose of human consumption in Islam. The Qur'an in different areas acknowledges the role of life on earth, the interconnectedness of living things, how Allah has created them in "communities" and how they interact together to sustain life. In many respects Islam recognizes what environmentalists call the "ecosystem".
3)Islam challenges "factory farming" practices which relegate the roles of animals to a "means to an end". Animals are not only food in this respect - the way they are treated in the factory farms. They are mistreated, abused, herded into small shelters, fed steroids and poisons - there sole purpose becomes the profit they generate. Islam opposes such treatment of animals (this is another reason to avoid eating un-halal meats, which are the product of factory farms, which abuse animals). Allah abhors such abuse of His creation, and so should we. Allah's creation are a sign of His greatness and we should respect that and not lose sight of His signs.
I hope this helps you and I would encourage you to read the verses in the Quran yourself. Good luck!
Achtung ;)
"Say: Have ye considered what provision Allah hath sent down for you, how ye have made of it lawful and unlawful ? Hath Allah permitted you, or do ye invent a lie concerning Allah ?" (QS. 10:59)