What Is Meant by Non-Naturalness and Non-Causality?

In the Śūraṅgama Sūtra, the Buddha said that all dharmas do not exist naturally on their own, nor do they arise from the combination of causes and conditions; rather, they are manifested by the nature of the tathāgatagarbha. For example, take the trees on a mountain: if they existed naturally, they would also perish naturally, and after perishing, would they grow back again? No, they would not. Moreover, many trees are planted by human hands; even those that were not planted by humans did not come into existence naturally either—they appeared gradually along with the emergence of the Earth.

Then did the trees come into being through the combination of causes and conditions? Neither is that so. On the surface, the appearance of trees seems to result from the combination of causes and conditions such as human planting, watering and irrigation, fertilizing, and sunlight, which allow them to grow. In reality, it is not so. These conditioned dharmas are all illusory, subject to arising, ceasing, and change, and have no real function. The real function belongs to the tathāgatagarbha; it is the tathāgatagarbha that aggregates the seeds of the five great elements to form them. Without the seeds of the five great elements, there would be no trees, and not even the cellular particles of trees would appear. Even these external conditioned dharmas are themselves aggregated from the seeds of the seven great elements of the tathāgatagarbha; there are no real conditioned dharmas. Therefore, trees possess the nature of the tathāgatagarbha. When sentient beings see trees, it is the wondrous function of the tathāgatagarbha's seeing nature—the Buddha-nature—and it is the wondrous nature of true suchness.