Karma in Jainism - Rationale

Rationale

Justice Tukol notes that the supreme importance of the doctrine of karma lies in providing a rational and satisfying explanation to the apparent unexplainable phenomenon of birth and death, of happiness and misery, of inequalities and of existence of different species of living beings. Sūtrakṛtāṅga, one of the oldest canon of Jainism, states:

Here in the east, west, north, and south many men have been born according to their merit, as inhabitants of this our world—some as Aryas, some as non-Aryas, some in noble families, some in low families, some as big men, some as small men, some of good complexion, some of bad complexion, some as handsome men, some as ugly men. And of these men one man is king.

— Sūtrakṛtāṅga, 2.1.13

Jains thus cite inequalities, sufferings, and pain as evidence for the existence of karma. The theory of karma is able to explain day-to-day observable phenomena such as inequality between the rich and the poor, luck, differences in lifespan, and the ability to enjoy life despite being immoral. According to Jains, such inequalities and oddities that exist even from the time of birth can be attributed to the deeds of the past lives and thus provide evidence to existence of karmas:

One is stout while another is lean; one is a master while another is a slave and similarly we find the high and the low, the mutilated and the lame, the blind and the deaf and many such oddities. The thrones of mighty monarchs are gone. The proud and the haughty have been humiliated in a moment and reduced to ashes. Even amongst the twins born of the same mother, we find one a dullard and another intelligent, one rich and another poor, one black and another white. What is all this due to? They could not have done any deeds while they were in their mother’s womb. Then, why then should such oddities exist? We have then to infer that these disparities must be the result of their deeds in their past births though they are born together at one time. There are many oddities in this world and it will have to be admitted that behind all this some powerful force is at work whereby the world appears to be full of oddities. This force is called 'karma'. We are unable to perceive karma by our naked eyes, yet we are able to know it from its actions.