Sri R. Krishnaswami Aiyer, M.A., B.L., writes about Karma in the Hindu Mind dated October, 1935:
a. Karmas Classified
Karmas are good, bad or mixed. The results of good Karmas are:
1. Purification of the mind, that is to say, the removal from the mind of its drossness which is the effect of thoughts of narrow selfishness and gross sensuality.
2. Happiness in the higher regions, during the period between the death and rebirth in this physical world. If the Karma is of an exceptional nature, the thinker may even be made an office-bearer with an authority in such higher regions.
3. Coming back, as man again, to earth-life with facilities for further purification of mind. If the Karma, however, is done without attachment to its fruits and the thinker has been going along the path of Jnana (knowledge) or along the higher regions of the path of Bhakti (devotion to the supreme universal Soul) having his mind completely purified and possessing faith in the revealed truth that he and the Divine Object of his devotion are in fact one in the self, he is not bound to return again to earth-life.
The results of bad Karmas are:
1. The mind becomes more and more impure.
2. Suffering in the nether region or hell during the period between the death and rebirth here.
3. If the Karma is very bad, after suffering in the nether region, the thinker is made to take his birth in this world in the lower animal or vegetable kingdom as part of his punishment. In some cases these lower births immediately follow the previous earth-life.
4. After undergoing his sufferings in hell or as a sub-human Jiva, the thinker comes again to assume a human body. He is then placed amidst very unfavourable environments to his progress onwards. These bad environments or impediments to advancement are in consequence of his own previous errors and misdoings.
Mixed Karmas are partly bad and its results are:
1. The mind becomes pure in certain respects and more impure in certain others.
2. The thinker suffers for some time in hell, and enjoys for some time in the happy regions above.
Afterwards he ordinarily takes birth here again as man.