俱舍論頌疏論本 2.91

2.91

釋曰：彼者，彼前所說，眼等名依也。及不共因者，眼等五根與眼等識為不共因，謂眼唯與自身眼識為所依性，名不共因。若色便通自他眼識，及通自他意識所取，是共因也。如眼既爾，乃至身觸應知亦然。眼等五根，由上二義，一者所依勝、二者不共因，故識得名隨根非境。然依論文，唯依五根明不共因，五境明共因，不就意法明者，謂意能生五識，非是不共因也。法唯意識緣，却名不共因也。雖意非不共因，而是意識所依性故，故隨所依名為意識。法雖是不共因，非所依故，不名法識。今此五根，由所依勝及不共因，境無此義，是故五識從根受稱。喻如鼓聲及麥芽等。鼓聲因手及鼓，但名鼓聲，不名手聲者，鼓有二義：一所依勝，聲依鼓變故；二不共因，但生鼓聲故。手闕二義，不名手聲。鼓喻根也，聲喻識也，手喻境也，況法可知。但名麥芽，不名水等芽者，麥有二義，准鼓說之。

The explanation says: 'That' refers to what was spoken of before: that the eye and the others are called 'bases'. 'And because of being the uncommon cause': the five faculties, the eye and the others, are the uncommon causes for the eye-consciousness and the others. That is to say, the eye serves as that which is relied upon solely for the eye-consciousness of one's own body, hence it is called an uncommon cause. Visible form, however, is common to the eye-consciousnesses of both oneself and others, and is common to being apprehended by the mental consciousnesses of both oneself and others; thus it is a common cause. As it is with the eye, so it should be known for up to the body and tangible objects. By virtue of the above two meanings—first, the superiority of being the basis, and second, being the uncommon cause—the consciousness receives its name following the faculty and not the object.

However, according to the text of the treatise, it is only with reference to the five faculties that the uncommon cause is clarified, and with reference to the five objects that the common cause is clarified; this is not explained with reference to mind and phenomena. This is because the mind is able to generate the five consciousnesses, so it is not an uncommon cause; while phenomena are the objects of mental consciousness alone, so they are instead called an uncommon cause. Although the mind is not an uncommon cause, because it is that which the mental consciousness relies upon, [the consciousness] is named mental consciousness in accordance with what it relies upon. Although phenomena are an uncommon cause, because they are not that which is relied upon, it is not named phenomena-consciousness. Now, these five faculties possess the superiority of being the basis and being uncommon causes, whereas their objects lack these meanings; therefore, the five consciousnesses receive their designations from the faculties.

It is like the sound of a drum, barley sprouts, and the like. The sound of a drum is caused by the hand and the drum, yet it is only called 'the sound of a drum' and not 'the sound of a hand'. This is because the drum has two meanings: first, the superiority of being the basis, because the sound changes in reliance upon the drum; second, being an uncommon cause, because it only generates the sound of a drum. The hand lacks these two meanings, so it is not called 'the sound of a hand'. The drum is a metaphor for the faculty, the sound is a metaphor for the consciousness, and the hand is a metaphor for the object; the parallel with the Dharma may be understood accordingly. It is called only a 'barley sprout' and not a 'water sprout', etc., because barley has the two meanings, which should be understood by analogy with the drum.