Changing human nature is changing habitual tendencies

Some people say that to understand human nature, one should watch the animal world more; once you understand the animal world, you will understand a part of human nature. Does this statement make sense? Why?

The six realms, ordered from lowest to highest, are: the hell realm, the ghost realm, the animal realm, the human realm, and the heavenly realm, along with the asura realm. The asura beings are distributed among the five realms above, so they can be counted as belonging to those five realms. In the cycle of rebirth of sentient beings, the animal realm is adjacent to the human realm, and their habitual tendencies are similar. After transmigrating from the animal realm to the human realm, human nature and animal nature are close and alike. As long as one has not eliminated the self-view (ātma-dṛṣṭi), one will return to the animal realm again, fully endowed with animal nature. This is hard to hear. Last time, when the topic of afflictions touched upon the animal realm, no one was willing to respond—I knew everyone was avoiding this issue. But avoiding it cannot solve the problem; only by facing the problem can one understand the principle and thereby resolve it.

Habitual tendencies are embodied in the manas. When a being transitions from an animal to a human, the mind consciousness changes, but the manas does not change. Deep down, one is still the same as animals or ghost beings, so in future rounds of rebirth one will still transmigrate into the three evil realms, fully endowed with the nature of beings in the three evil realms.

Do not care too much about the small amount of merit you have as a human—fame, profit, power, status, and race. Once you fall into the three evil realms, you are nothing at all, not even the equal of an ordinary person. Therefore, having encountered the Buddhadharma, one should focus on cultivating the manas and transforming the manas. Once the manas is transformed, the attributes of one's mental nature change, becoming distinct from the beings of the three evil realms, and the retributive results will be different.

To change yourself, you must understand yourself; to understand yourself, you must not only observe yourself and observe your own kind, but also observe the animal realm and the ghost realm, because they are similar and roughly alike. Once you have understood all of these, you will have fully understood yourself; and only by understanding yourself can you find a way to change yourself.