Why does Jainism strongly promote the principle of Ahimsa?
Jains believe in the existence of soul; and that each living being has a soul. Jains also show logically that the nature of the soul is that of non-harming. It is due to the soul being bound by Karmic particles that keep us humans in these material bodies that need to eat.
As a person lives a life that reduces the influence of the Karmic particles, the person’s non-harming character naturally will become stronger; and manifest itself in such activities as trying to watch out very carefully, and avoid doing even the slightest possible harm to any living being. In other words, Jains maintain that if we want to experience the full potential of the nature of our soul, that is non-harmingness, we should try to duplicate it in all our actions.
In Jainism, Ahimsa means non‑hurting as described above. Therefore, whenever our actions cause himsa (hurting), not only does our soul accumulate karmas but even the souls on the other side accumulate karma if they have minds (e.g., souls of animals, birds, fish, etc.).
Those karmas could be any of eight karmas, but we would discuss three of them over here which are Antaraya, Vedniya, and Ayushya Karmas.
When we deprive any living being of its livelihood, or its vital capabilities, it will come and hound us sometimes. The story of Lord Rushabhdev is very well-known for this. During his last life, while he was a king one day he advised his fellow farmer citizens to cover the mouths of the oxen so that they would not eat the grains they were working around. But, he forgot to tell them that they should remove the mouth cover as soon as the work was over. Those ignorant people kept on that mouth cover, and after some time they started wondering when to feed them. So they went back and asked King Rushabh about when they were suppose to feed them. The King realized his mistake and explained to those workers that they should have taken off the mouth cover as soon their work was over and feed them. But because oxen suffered hunger due to King Rushabh’s oversight, he accumulated Antaraya Karma. When this karma matured, it caused him to go without any food (starvation) for a little over eleven months when he became a monk in a later part of the same life. So can you imagine if we starve or deprive someone of their vitality, through cruel means, what would happen to us?
The same way, when we cause suffering to others, we accumulate Ashata Vedniya karma and when that matures, it would bring us sufferings and unhappiness. Look at the slaughterhouses, laboratories, cosmetic manufacturing, or any use of animals, and you will see nothing but tortures, and even death. Why any sensible person of their right mind, and particularly a Jain, would do, or encourage, such activities even though he or she would have to suffer later on? Therefore, Jains would not participate in any activity which would cause any harm to others and would not also ask, or encourage, anyone else to do it either. Now, you should understand that suffering in this world is generated from own selves. It is never late to turn back the clock to the right path by paying respect to other living beings as a whole rather than just to humans only.
Similarly, when we take away someone’s life, we must realize, what would be coming to us. We would accumulate such an Ayushya karma, that it would make our life short, or end it prematurely. Why would we put ourselves in such a situation? What happens if that life happens to be a human life, then we would miss an opportunity for spiritual pursuit. Therefore, we need to protect other lives, so that our lives are protected and we can be happy and without obstacles.
So in short by observing Ahimsa, not only we are protecting the vitality of other living beings, but in reality we are helping ourselves the most. That is why Jains say “Ahimsa Parmo Dharma,” because by observing Ahimsa, everyone is able to stop his/her own decline and put him/herself forward to the higher spiritual pursuit.