Why the animals should be slaughtered in a particular way?

By:
Ayatullah Makarim Shirazi & Ayatullah Ja'far Subhani
Question: In Islam, some rules and regulations are stipulated for slaughter of animals. For example, all the four veins in the neck should be cut and to say Bismillah etc. If these conditions are not fulfilled, meat of that animal is not fit for eating. Though many people in the world overlook these rules and use the meat of such animals and there is no harmful effect on them. Explain what is the purpose of these regulations?
Answer: It seems that by these regulations Islam wants to fulfill three purposes:
First is to get away from the traditions of idol-worshippers, who use to cut the throat of their animals by taking the name of the idol. That is why taking the name of Allah was considered to be essential part of this slaughter.
The main function of which is to destroy the thought of idol-worship and secondly to drain out blood from the animal so that it does not remain in the layers of meat, and should not be eaten along with the flesh. Medical science of today has discovered so many harms in food containing blood. Other than this, blood is always contaminated with different kinds of germs. It is also proved by experience that food items having blood create such mentality and peculiarities in the humans, which are not preferable. Feebleness of sensitiveness, tyranny and hardheartedness is included in these.
The third purpose is that the animal should die as soon as possible and it should not suffer agony for a longer period. As this is against the spirituality, i.e. soul of humanity. This purpose is possible by cutting four veins of the throat of the animal.
This is the summary of the three purposes with regard to animal slaughter prescribed by Islam and that those purposes can be achieved by implementing these rules.