Can the Fruits Attained in Hinayana Regress?

When an arhat of the fourth fruit returns to the mundane world, he regresses from the fourth fruit back to the third fruit; after renouncing the world again and distancing himself from worldly life, he once more becomes an arhat of the fourth fruit. If an arhat of the fourth fruit can regress, the third fruit can certainly regress as well. Meditative concentration can also disappear, and mental activities can regress. Even the second fruit can regress back to the first fruit. An arhat of the fourth fruit has eradicated grasping, yet he can still regress and give rise to grasping again—how much more so the third fruit.

There are specific examples in the Buddhist scriptures as proof. Without having attained that fruit, one cannot truly understand it. Standing at a lower level, one cannot see clearly the higher level, nor can one comment on it. Grasping the truth of facts can only come through personal experience. It is just like many people today who, clearly still at the stage of ordinary beings, spend all day debating the realms of the buddha-stage, arguing until they are red in the face—it is all armchair theorizing, utterly meaningless.