Hello Lal, thank you for your welcome and your reply. If I may respond:
> But someone buying meat at the supermarket is not taking a life. That animal was killed by someone else days ago.
True, however to put it in a familiar phrase, and as you allude to a little later, when the buying stops, the killing stops too. Paying someone else to kill on one’s behalf does not absolve one of the karmic repercussions, although I believe they would not be as bad as the one who did the actual killing. I understand your point about the different levels of karmic repercussions, eg: hurting an Arahant is worse than killing an animal. However, killing an animal is worse than not killing an animal.
To address your point that by living we inadvertently hurt other beings, for example by driving, by walking in the garden, by boiling water. My understanding with regards to the taking of life, is that one should not take the life of a being that does not want to die, or equivalently, of a being that would suffer through the process of being killed. Obviously the animals killed for meat suffer during the process of their slaughter. However it is questionable whether the micro-organisms in water suffer when we boil the water. Bacteria lack the physiology of a nervous system to feel pain in the way more complex organisms do. Their behaviour also indicates that they do not try to avoid death the same way that mammals do, relying instead on their enormous numbers and average that some will always survive to propagate themselves. These points indicate that bacteria may not suffer in the same way that mammals do.
I have heard it argued that the precept against killing applies to beings with a central nervous system capable of suffering in a way that we would relate with, having a central nervous system ourselves. I think that is a good criteria to use and thus I myself do not count the bacteria in water being boiled as breaking of the first precept.
The above argument notwithstanding, your point that just by living we harm other beings is still true. However I believe we should take the approach of minimizing the number of beings killed. Refraining from supporting meat production, in the way meat is produced today does minimize this suffering.
>An uncountable number of living-beings are killed when a farmer prepares the soil for planting, and even when harvesting the crop.
The counter to this is that however many die when a farmer grows and harvests a crop, orders of magnitude more die when that crop is fed to animals who are then fed to humans, instead of feeding the crop directly to humans. This is because we must spend so much more resources to breed the animals to the point where they can reproduce and be ready for slaughter.
I would also like to draw attention to the point that although many animals do die inadvertently as we walk through the garden, drive to work, or even through the production of vegetables we consume, the death of animals raised for food is not inadvertent. Their deaths cannot be counted as inadvertent deaths, but as deliberate systematic mass-produced slaughter with a volition of greed for both money and the craving for flesh being the motivation behind it. I apologize if the words I use in the previous sentence sound rather harsh to meat-eaters. Nevertheless they are true.