（indriya） 'Workings'， 'mechanism'， 'faculty'， 'ability.' （1） The 根 of plants and trees implies their ability to grow and develop and in still life into their trunks and branches; it is in this sense regarded as "root." （2） The term also has the meaning of 'organ'--that which gives rise to perception. Therefore it is used as a name for the five sense organs （五根）. These five organs are invisible and are created by transformation of the four elements （四大）， and have the ability to see， hear， and so forth. Though they are invisible and pure， they do theoretically occupy space， and are therefore able to be classified as 'form' elements in the classification system of the Faxiang school. （3） Ability， capacity， nature， faculty， of which there are generally sharp， average and dull. The particular capabilities that a certain individual has for understanding a certain level of teaching and attaining enlightenment.