Why Do Different Practitioners Have Different Levels of Realization?

When contemplating the five aggregates, if one has very deep meditative concentration (samādhi), one's contemplation will be very deep and subtle, able to penetrate ever deeper into the meaning of the Dharma, thereby unraveling the mysteries of the Dharma layer by layer. When engaging in contemplative practice (vipaśyanā-caryā) and deliberation, one must proceed slowly, finely, and deeply, comparing against one's own bodily, verbal, and mental actions in the present moment, investigating and gathering evidence over as wide a range as possible to prove that the five aggregates are not the self. One must investigate why this aspect is not the self, why that aspect is not the self, trying to find evidence one by one, asking "why," and resolving this question of "why." One must contemplate deeply and subtly. If one only has a formal, intellectual understanding without truly internalizing it in one's mind, then all theoretical knowledge is empty and hollow, unable to solve the fundamental and practical problems. 

How does one engage in contemplative practice and deliberation? For example, in contemplating that the physical body is not the self—"not the self" is a conclusion, but it is the Buddha's conclusion, not our own. Therefore this conclusion has nothing to do with us. Only after contemplative practice, when we ourselves have genuinely and truly arrived at this conclusion, does it become our own—the crystallization of our own wisdom—and only then does it yield the merit and benefit of liberation. The Buddha's conclusion is merely a starting point, serving as a reference for developing our own wisdom. We can follow this conclusion and contemplate backward: Why is the physical body not the self? Because the physical body is empty. Why is the physical body empty? Because the physical body is suffering. Why is the physical body suffering? This is the entry point of our initial contemplative practice, requiring us to slowly deliberate and search for various kinds of evidence. 

Finally, we arrive at the conclusion that the physical body is indeed not the self, and this eradicates the view of the body and the view of self (satkāya-dṛṣṭi). After contemplative practice, the fruit each person attains is not necessarily the same, because the degree to which the view of the body has been eradicated differs, with certain variations—it depends on the degree of realization and the degree of cultivation and practice. Even attaining the first fruit, srotāpanna, is divided into different degrees, and the degree of benefit and transformation of body and mind also differs. For example, children all enter the first grade, yet their level of learning within the same class varies. Attaining the fruit is like graduation, so at graduation each person's level is also different, and some graduate early while others graduate late. Each practitioner's level of realizing the Dharma differs because the scope, angle, and depth of their investigation differ, their power of deliberation differs, and the depth and strength of their evidence differ; consequently, the wisdom they obtain differs. With different wisdom, the degree of change in one's conduct also differs. The deeper and more subtle the deliberation, the better the meditative concentration; the better the meditative concentration, the deeper and more subtle the deliberation; and thus the deeper and more ultimate the degree of realization, and the more thorough the transformation of one's mental activities.