What Is the Precept of Guarding the Mind?

Observing mental precepts means preventing the mind from generating thoughts and refraining from afflictions such as greed, hatred, and delusion. This is extremely difficult and requires the complete eradication of afflictions; it is challenging even to suppress them, as there are often moments when suppression fails. In the present world, even physical and verbal precepts are hard to uphold, with numerous opportunities to transgress. Slight lapses in self-restraint lead to violations of physical and verbal precepts.

Why do people violate physical and verbal precepts? It is due to the mind. When the mind is afflicted by greed, hatred, and delusion, it compels the body and speech to create unwholesome karma. If one can guard the mind, the body and speech will not transgress or create unwholesome karma. If the mind does not violate precepts, then regardless of how the body and speech act, it is not considered a transgression, because there is no mental activity driven by greed, hatred, or delusion. All precepts are measured by the presence or absence of mental intent, but ordinary people find it difficult to discern others' minds and thus use their physical and verbal actions as the standard. Consequently, errors in judgment frequently occur.

The Hinayana discipline takes physical and verbal karma as the standard; as long as physical and verbal actions do not violate precepts, the state of mental conduct is irrelevant. Mahayana bodhisattvas, however, adhere to the standard of mental precepts, where even the arising of thoughts should not be for self-benefit. Genuine Mahayana precepts are exceedingly difficult to uphold. For instance, the bodhisattva precepts in the Yogācārabhūmi-śāstra were established for bodhisattvas on the bhūmis (stages of awakening) from the first bhūmi onward. Pre-bhūmi bodhisattvas, who have not eradicated afflictions like greed, hatred, and delusion, cannot observe them; any physical or verbal transgression constitutes a violation. For post-bhūmi bodhisattvas, mental conduct is the standard: as long as the mind acts for the benefit of sentient beings, it is not considered a transgression.