Pratyekabuddhas all realize the twelve links of dependent origination, not merely understand them.

The Āgama sūtras describe the pratyekabuddhas' forward contemplation of the twelve links of dependent origination and their reverse contemplation of the twelve links of dependent origination. Although the language describing the pratyekabuddhas' investigation is rather concise and the introduction to their practice is rather simple, the pratyekabuddhas' cultivation was by no means easy; the process in between was winding and arduous. When actually engaging in contemplative practice (vipaśyanā-caryā) and deliberation, they were all in profound meditative concentration (samādhi): the mind consciousness deliberated on one side while the manas deliberated (manasikāra) simultaneously, so of course the results were all realizations. Without meditative concentration, there is only the mind consciousness's deliberation, without the manas's simultaneous deliberation, so realization is impossible—one may arrive at an intellectual understanding, but understanding is of no use.

As for the specific practical process of the pratyekabuddhas' cultivation, the Buddha could not disclose it in detail; the purpose was to let later people apply effort themselves and realize it through practice. Saying too much easily leads people to mere intellectual understanding, and their effort would not be brought to full fruition, so it could only be stated in that simple way. Within those simple deliberations and dialogues, one must never think that the pratyekabuddhas arrived at a result merely through the mind consciousness's reasoning and logical deliberation—to say so would be tantamount to slandering the pratyekabuddhas. The pratyekabuddhas' meditative concentration was extremely profound; the mind consciousness's function absolutely could not occupy the dominant position and could not overwhelm the manas; the manas's investigation and deliberation had to occupy the dominant position. The deeper a person's meditative concentration, the more the manas is employed; conversely, the mind consciousness is used more, relying mainly on the mind consciousness's imagination, reasoning, and speculation, and the manas cannot be put to use.

By the same token, the arhats all possessed very deep meditative concentration. In observing the five aggregates (pañca-skandha) of the past and the future, they did not use the mind consciousness's reasoning, nor inference or non-valid cognition; everything was direct perception with the manas participating. Because those physical bodies were identical to the current body of the five aggregates, belonging to the same kind, by realizing the current one, one knows the past and future ones. For example, suppose there is now a batch of products that need to be inspected; because the products are all identical, inspecting a sample of just one of them reveals how the entire batch of products is. This of course does not include the case where someone has mixed in other products. Under the premise that everything is exactly identical, inspecting one or a few is enough to know the whole. Therefore, the arhats' realizations were all realized through direct perception—what it is, it is; there was no such deliberative mode of imagination, no deliberative mode of comparison. For a person without meditative concentration, the mind consciousness's deliberative functions of inference and non-valid cognition are unavoidable.