The Sanlun school, also known as the Three Treatise school, is a Chinese Madhyamaka school of Buddhism that emerged during the 6th century. This school is based on the teachings of Nagarjuna and his disciples, and it places a strong emphasis on the concept of emptiness and the Middle Way.

In regards to the concept of karma, the Sanlun school believes that it is an essential aspect of Buddhist teachings and plays a significant role in the process of attaining enlightenment. Karma refers to the law of cause and effect, where actions and intentions have consequences that shape one's present and future experiences.

According to the Sanlun school, karma is not a physical or tangible entity but a mental phenomenon. It is a result of the deluded mind and its attachment to the concept of self. The school teaches that all phenomena, including karma, are ultimately empty of inherent existence and are dependent on causes and conditions. Therefore, karma is not a fixed or predetermined outcome but is constantly changing and evolving.

The Sanlun school also emphasizes the interconnectedness of all beings and phenomena. This means that one's actions and intentions not only affect oneself but also have an impact on others and the environment. Therefore, one must be mindful of their thoughts, words, and actions as they can create positive or negative karma.

The school also teaches that karma is not limited to this lifetime but extends to past and future lives. This concept is closely related to the belief in reincarnation, where one's actions in this life will determine their experiences in the next life. The Sanlun school believes that the cycle of rebirth can only be broken through the realization of emptiness and the Middle Way.

In summary, the Sanlun school views karma as a mental phenomenon that is dependent on causes and conditions. It plays a crucial role in the process of attaining enlightenment and is interconnected with the concept of emptiness and the Middle Way. By understanding the true nature of karma, one can break free from the cycle of suffering and attain liberation.