What Are the Internal and External Factors of Enlightenment (bodhyaṅga)?

The first of the seven factors of enlightenment is the mindfulness factor of enlightenment. The internal mindfulness factor is the mindfulness of the manas, while the external mindfulness factor is the mindfulness of the mind consciousness. When the manas lacks the mindfulness factor of enlightenment, the mindfulness factor of enlightenment is not accomplished, and the investigation-of-dharmas factor of enlightenment cannot manifest. Therefore, the manas definitely possesses the mental factor of mindfulness. The Hīnayāna sūtras already implicitly speak of the manas's mental factor of mindfulness, let alone the Mahāyāna sūtras. It is merely that sentient beings, heavy with ignorance, cannot understand the Buddhist sūtras and are unable to discern this.

Judging from the World-Honored One's description of the seven factors of enlightenment, the manas possesses the investigation-of-dharmas factor, the diligence factor of enlightenment (true diligence), the joy factor of enlightenment (the manas does not merely have neutral feeling), the tranquility factor of enlightenment, the meditative concentration factor of enlightenment (in accord with samādhi), and the equanimity factor of enlightenment. Only afterward, when the mental activities conform to the Noble Eightfold Path, can the conditions for attaining the fruits of the Hīnayāna be fulfilled, so that one can eliminate self-view (ātma-dṛṣṭi) and realize the first fruit; otherwise, all such fruits are false fruits, plastic fruits. When the conditions are not fulfilled and the causes and conditions are not complete, forcibly guiding someone can only yield a false fruit.

Among the seven factors of enlightenment, there is the investigation-of-dharmas factor. When one cultivates to this stage, one gains the ability to discern. However, when something far exceeds one's current level, one again lacks the capacity for discernment, and so one must continue cultivating. The investigation-of-dharmas factor must be progressively advanced until it is perfectly and completely fulfilled, so that one can immediately and correctly discriminate all dharmas without doubt.