Question:
I recently read that for the first 1600 years of the world's existence man was not allowed to eat meat. Only after surviving the devastation of the Flood did G-d permit Noah to eat meat. If G-d's original plan was that we should be vegetarians why did this change after the flood?
Answer:
The 15th Century philosopher Rabbi Yosef Albo explains that although the original G-dly plan was that man was to rule over all the animals, nevertheless He instructed that man should not to take the life of any living being so as not to ingrain any act of killing in the human character. But the people of the early generations misinterpreted this to mean that man and animal were equal with similar expectations and standards.
Rabbi Albo explains that this concept was in fact the background to the dispute between Cain and Abel which led to Abel's murder: The Torah tells how Cain brought a sacrifice of the produce of the land while Abel offered a sacrifice from the animals of his flock. G-d accepted Abel's sacrifice but not Cain's. The reason Cain did not offer an animal sacrifice was because he regarded men and animals to be equals and accordingly felt that that he had no right to take the life of an animal even as an act of Divine worship. Abel on the other hand appreciated man's sovereignty over animals and understood that it was appropriate to use animals in the service of G-d. Cain was so confirmed in his opinion that man and animal are inherently equal that he was led to an even more grievous conclusion that just as man is entitled to take the life of an animal (which he understood by G-d's acceptance of Abel's sacrifice) so too he is entitled to take the life of his fellow man. As a result he murdered his brother.
This position was adopted by the succeeding generations as well. It was precisely the notion that men and animals are equal that led, not to the renunciation of causing harm to animals and to concern for their welfare, but rather to the conclusion that violence against one's fellow man was equally acceptable. It was this total breakdown of the social order that prompted G-d to rearrange things by means of The Flood.
To impress upon man the Divine purpose and moral obligation entrusted to him and his sovereignty over the animal kingdom, G-d told Noah that humankind could now eat animal flesh. Our rabbis consequently tell us that when eating meat, we should not do so to merely satisfy our materialistic lust - as an animal would - but rather with the purpose of elevating the animal to the level of the human being. Our dominion over animals reminds us of our divine mandate to perfect the world.