Has anyone found a satisfactory answer in the suttas on why bad kamma results in bad rebirth or vice versa? I know ‘satisfactory’ is subjective but would like to hear from the forum, nonetheless;
Nature doesn’t seem to give any indication of a moral order; its generally survival of the fittest and even altruism/co-operation found in animals can be explained in evolutionary terms being advantageous for the group;
There are certain suttas which seem to address this though its not entirely clear/satisfactory to me;
They seem to hint at “similarity” in nature as a reason;
Passages which say having done “sabyabajjha” (with affliction/harm) kamma, one is born in a loka(world/realm) with byabajjha; Having born there, one undergoes experiences which are with byabajjha - that is ekantadukkha (wholly painful/exceedingly painful) like in Niraya;
(ref MN 57 - SuttaCentral)
A person samsappati (is crooked/creepy) in thought, word and deed; He is born as a creeping creature.
(ref AN 10.216 Samsappaniya sutta - SuttaCentral)
To my mind, these are not entirely satisfactory;
For example, the first sutta talks of world/realm which is ekantadukkha - exclusively /predominantly painful i.e. Niraya and contrasts it with realm which is exclusively/predominantly pleasurable i.e. of subhakinna devas; If they mean realms which are ‘exclusively’ painful or pleasurable as the context seems to imply, it is difficult to imagine them arising/evolving naturally; There are no such examples that we know of from nature;
For comparison, am giving the explanation that can be inferred from the samkhya (and samkhya influenced) texts from India
In Samkhya philosophy, there seems to be an explanation which is consistent, with its own framework, at least, on how beings move up & down the birth chain and why bad deeds lead to lower birth;
All creatures are said to possess three “gunas” (characteristic/trait/nature) - Sattva (knowledge/light), Rajas (passion/raga+dvesa/dust) and Tamas (ignorance/darkness/moha) in differing combinations.
Animals and lower creatures, by nature, are Tamas predominant; Devas are sattva predominant and humans are Rajas predominant.
Actions done in ignorance/without regard to consequences are tamasic including those harmful to others; Restrained knowledgeable actions are Sattvik and those involving raga/dvesa unrestrained are Rajasic.
So a human, who does Tamasic deeds and whose nature becomes Tamas dominant, is reborn as an animal - due to the likeness in “guna”; A human who is more sattvik is akin to devas and hence born in the deva realm;
Ref: Samkhya karika(non theistic), Bhagavad Gita(theistic), Manu smriti (theistic)
I noted this here to show that samkhya also seems to employ the principle of “similarity” in nature to account for rebirth phenomenon; (Whether guna is actual physical matter or a mental state is differently mentioned in different texts)
PS: I do realise a simple answer to the question in title would be: because thats the way it is and Buddha observed it to be so