A yaga or sacrifice takes shape with the chanting of the mantras, the invoking of the deity and the offering of havis (oblation). The mantras are chanted (orally) and the deity is meditated upon (mentally). The most important material required for homa is the havis offered in the sacrificial fire-- in this "work" the body is involved. So, altogether, in a sacrificial offering mind, speech and body (mano-vak-kaya) are brought together.
Ghee (clarified butter) is an important ingredient of the oblation. While ghee by itself is offered as an oblation, it is also used to purify other sacrificial materials - in fact this is obligatory. In a number of sacrifices the vapa(fat or marrow) of animals is offered.
Is the performance of a sacrifice sinful, or is it meritorius? Or is it both?
Madvacharya was against the killing of any pasu for a sacrifice. In his compassion he said that a substitute for the vapa must be made with flour and offered in the fire. ("Pasu" does not necessarily mean a cow. In Sanskrit any animal is called a "pasu". )
In his Brahmasutra, Vyasa has expounded the nature of the Atman as found expressed in the Upanishads which constitute the jnanakanda of the Vedas. The actual conduct of sacrifices is dealt with in the Purvamimamsa which is the karmakanda of the Vedas. The true purpose of sacrifices is explained in the Uttaramimamsa, that is the jnanakanda. What is this purposse or goal? It is the cleansing of the consciousness and such cleansing is essential to lead a man to the path of jnana.
The Brahmasutra says: "Asuddhamiti cen na sabdat". The performance of sacrifices is based on scriptural authority and it is part of the quest for Self realisation. So how can it be called an impure act? How do we determine whether or not an object or an act is impure or whether it is good or bad? We do so by judging it according to the authority of of the sastras. Vyasa goes on to state in his Brahmasutra that animal sacrifice is not sinful since the act is permeated by the sound of the Vedas. What is pure or impure is to be known by the authority provided by the Vedas or rather their sound called Sabdapramana. If sacrifices were impure acts according to the Vedas, they would not have accepted them as part of the Atmic quest. Even if the sacrificial animal is made of flour (the substitute according to Madhvacharya) it is imbued with life by the chanting of the Vedic mantras. Would it not then be like a living animal and would not offering it in a sacrifice be taken as an act of violence?
Tiruvalluvar says in his Tirukkural that not to kill an animal and eat it is better than performing a thousand sacrifices in which the oblation is consigned to the fire. You should not take this to mean that the poet speaks ill of sacrifices.
What is in accordance or in pursuance of dharma must be practised howsoever or whatsoever it be. Here questions of violence must be disregarded. The Tirukkural says that it is better not to kill an animal than perform a thousand sacrifices. From this statement it is made out that Tiruvalluvar condemns sacrifices. According to Manu himself conducting one asvamedha (horse sacrifice) is superior to performing a thousand other sacrifices. At the same time, he declares that higher than a thousand horse sacrifices is the fact of one truth. If we say that one thing is better than another, the implication is that both are good. If the performance of a sacrifice were sinful, would it be claimed that one meritorious act is superior to a thousand sinful deeds? You may state that fasting on one Sivaratri is superior to fasting on a hundred Ekadasis. But would you say that the same is better than running a hundred butcheries? When you remark that "this rite is better than that rite or another", it means that the comparison is among two or more meritorious observances.
In the concluding passage of the Chandogya Upanishad whwre ahimsa or non-violence is extolled you find these words, "Anyatra tirthebhyah". It means ahimsa must be practised except with regard to Vedic rites.
Considerations of violence have no place in sacrifices and the conduct of war.
If the ideal of non-violence were superior to the performance of sacrifices, it would mean that "sacrifices are good but non-violence is better". The performance of a thousand sacrifices must be spoken of highly but the practice of non-violence is to be regarded as even higher: It is in this sense that the Kural stanza concerning sacrifices is to be interpreted. We must not also forget that it occurs in the section on renunciation. What the poet want to convey is that a sanyasin does better by abstaining from killing than a householder does by conducting a thousand sacrifices. According to the sastras also a sanyasin has no right to perform sacrifices.
There are several types of sacrifices. I shall speak about them later when I deal with "Kalpa" (an Anga or limb of the Vedas) aaand "Grihasthasrama" (the stage of the householder). What I wish to state here is that animals are not killed in all sacrifices. There are a number of yagnas in which only ghee (ajya) is offered in the fire. In some, havisyanna (rice mixed with ghee) is offered and in some the cooked grains called "caru" or "purodasa", a kind of baked cake. In agnihotri milk is poured into the fire; in aupasana unbroken rice grains (aksata) are used; and in samidadhana the sticks of the palasa (flame of the forest). In sacrifices in which the vapa of animals is offered, only a tiny bit of the remains of the burnt offering is partaken of - and of course in the form of prasada.
One is enjoined to perform twenty-one sacrifices. These are of three types:pakayajna, haviryajna and somayajna. In each category there are seven subdivisions. In all the seven pakayajnas as well as in the first five haviryajnas there is no animal sacrifice. It is only from the sixth haviryajna onwards (it is called "nirudhapasubandha") that animals are sacrificed.
"Brahmins sacrificed herds and herds of animals and gorged themselves on their meat. The Buddha saved such herds when they were being taken to the sacrificial altar, " we often read such accounts in books. To tell the truth, there is no sacrifice in which a large number of animals are killed. For vajapeya which is the highest type of yajna performed by Brahmins, only twenty-three animals are mentioned. For asvamedha (horse sacrifice), the biggest of the sacrifices conducted by imperial rulers, one hundred animals are mentioned.
It is totally false to state that Brahmins performed sacrifices only to satisfy their appetite for meat and that the talk of pleasing the deities was only a pretext. There are rules regarding the meat to be carved out from a sacrificial animal, the part of the body from which it is to be taken and the quantity each rtvik can partake of as prasada (idavatarana). This is not more than the size of a pigeon-pea and it is to be swallowed without anything added to taste. There may be various reasons for you to attack the system of sacrifices but it would be preposterous to do so on the score that Brahmins practised deception by making them a pretext to eat meat.
Nowadays a large number of animals are slaughtered in the laboratories as guinea-pigs. Animal sacrifices must be regarded as a little hurt caused in the cause of a great ideal, the welfare of mankind. As a matter of fact there is no hurt caused since the animal sacrificed attains to an elevated state.
There is another falsehood spread these days, that Brahmins performed the somayajnas only as a pretext to drink somarasa (the essence of the soma plant). Those who propagate this lie add that drinking somarasa is akin to imbibing liquor or wine. As a matter of fact somarasa is not an intoxicating drink. There is a reference in the Vedas to Indra killing his foe when he was "intoxicated" with somarasa. People who spread the above falsehoods have recourse to " arthavada" and base their perverse views on this passage.
The principle on which the physiology of deities is based is superior to that of humans. That apart, to say that the priests drank bottle after bottle of somarasa or pot after pot is to betray gross ignorance of the Vedic dharma. The soma plant is pounded and crushed in a small mortar called "graha". There are rules with regard to the quantity of essence to be offered to the gods. The small portion that remains after the oblation has been made, "huta-sesa", which is drunk drop by drop, does not add up to more than an ounce. No one has been knocked out by such drinking. They say that somarasa is not very palatable. .
The preposterous suggestion is made that somarasa was the coffee of those times. There are Vedic mantras which speak about the joy aroused by drinking it. This has been misinterpreted. While coffee is injurious to the mind, somarasa cleanses it. It is absurd to equate the two. The soma plant was available in plenty in ancient times. Now it is becoming more and more scarce: this indeed is in keeping with the decline of Vedic dharma. In recent years, the Raja of Kollengode made it a point to supply the soma plant for the soma sacrifice wherever it was held.
For a general background, please see here