四分

With respect to the relationship between the subjective consciousness and the object phenomena, there are four mental functional portions in each of the eight consciousnesses. They are interdependent in nature.

1. The objective or the seen portion ( 相分 ), ie. Lakṣaṇa-bhaga - all phenomena presented and revealed in mind. The seen portions of the first five mental faculties ( eye, ear, nose, tongue and body ) are the five 'dusts' ( form, sound, smell, taste and touch ). The seen portion of the Manas consciousness is the seeing portion of the Ālaya consciousness, while the seen portion of the Ālaya consciousness is the seed of all mental faculties and all matters and phenomena.
2. The subjective or the seeing portion ( 見分 ), ie. Darśana-bhaga - the illumining or seeing effect of the 'dust', which is transformed to its seen portion.
3. The self-realizing or the self-assuring portion ( 自証分 ) - the portion that knows the seeing portion has seen the 'dusts'. This function of cognition is called 'self-realization', or 'self-assurance' or 'self-certification', without which no knowledge can be attained.
4. The re-assuring portion ( 証自証分 ) - the portion that realizes the third portion upon internal reflection. It concludes all the effects taken from the mental faculties.

For example, a piece of paper presented in mind is the seen portion, while the seeing portion is the measuring instrument to see its length and width. The self-assuring portion cognizes how long and how wide it is, according to the measurements. The re-assuring portion recognizes the accuracy of the measurements.