In its inviolability, the law of karma is like the other laws of nature. However, the rigorousness of the operation of karmic laws does not come to the soul as the oppressiveness of some external and blind power but as something involved in the rationality of the scheme of life. Karmic determination is the condition of true responsibility. It means that an individual will reap as he sows. What a person gathers by way of experience is invariably connected with what he does. If a person has done an evil turn to someone, he must accept the penalty for it and welcome the evil rebounding upon himself. If he has done a good turn to someone, he must also receive the reward for it and enjoy the good rebounding upon himself. What he does for another he has also done for himself, although it may take time for him to realize that this is exactly so. The law of karma is an expression of justice and a reflection of the unity of life in the world of duality.
-Discourses 7th Ed., p332