Killing of animals before the advent of Lord Buddha was the most prominent feature of the society. People claimed that these were Vedic sacrifices. When the Vedas are not accepted through the authoritative disciplic succession, the casual readers of the Vedas are misled by the flowery language of that system of knowledge. In the Bhagavad-gītā a comment has been made on such foolish scholars (avipaścitaḥ). The foolish scholars of Vedic literature who do not care to receive the transcendental message through the transcendental realized sources of disciplic succession are sure to be bewildered. To them, the ritualistic ceremonies are considered to be all in all. They have no depth of knowledge. According to the Bhagavad-gītā (BG 15.15), vedaiś ca sarvair aham eva vedyaḥ: the whole system of the Vedas is to lead one gradually to the path of the Supreme Lord. The whole theme of Vedic literature is to know the Supreme Lord, the individual soul, the cosmic situation and the relation between all these items. When the relation is known, the relative function begins, and as a result of such a function the ultimate goal of life or going back to Godhead takes place in the easiest manner. Unfortunately, unauthorized scholars of the Vedas become captivated by the purificatory ceremonies only, and natural progress is thereby checked.
To such bewildered persons of atheistic propensity, Lord Buddha is the emblem of theism. He therefore first of all wanted to check the habit of animal-killing. The animal-killers are dangerous elements on the path going back to Godhead. There are two types of animal-killers. The soul is also sometimes called the "animal" or the living being. Therefore, both the slaughterer of animals and those who have lost their identity of soul are animal-killers.
Mahārāja Parīkṣit said that only the animal-killer cannot relish the transcendental message of the Supreme Lord. Therefore if people are to be educated to the path of Godhead, they must be taught first and foremost to stop the process of animal-killing as above mentioned. It is nonsensical to say that animal-killing has nothing to do with spiritual realization. By this dangerous theory many so-called sannyāsīs have sprung up by the grace of Kali-yuga who preach animal-killing under the garb of the Vedas. The subject matter has already been discussed in the conversation between Lord Caitanya and Maulana Chand Kazi Shaheb. The animal sacrifice as stated in the Vedas is different from the unrestricted animal-killing in the slaughterhouse. Because the asuras or the so-called scholars of Vedic literatures put forward the evidence of animal-killing in the Vedas, Lord Buddha superficially denied the authority of the Vedas. This rejection of the Vedas by Lord Buddha was adopted in order to save people from the vice of animal-killing as well as to save the poor animals from the slaughtering process of their big brothers who clamor for universal brotherhood, peace, justice and equity. There is no justice when there is animal-killing. Lord Buddha wanted to stop it completely, and therefore his cult of ahiṁsā was propagated not only in India but also outside the country.