This sense of hearing, then, having its origin in the principle of ahaṃkāra, behaves like iron, and is drawn by the sounds originated and located in the mouth of the speaker acting as loadstone, and transforms them into its own successive modifications (_vṛtti_) and thus senses the sounds of the speaker. And it is for this reason that for every living creature, the perception of sound in external space in the absence of defects is never void of authority. Thus Pancasikha also says, as quoted in _Vyāsa-bhāshya_, III. 41: “To all those whose organs of hearing are situated in the same place (at different times) the ākāśa sustaining the sense of hearing is the same.” The ākāśa, again, in which the power of hearing is seated, is born out of the soniferous tanmātra, and has therefore the quality of sound inherent in itself. It is by this sound acting in unison that it takes the sounds of external solids, etc. This then proves that the ākāśa is the substratum of the power of hearing, and also possesses the quality of sound. And this sameness of the situation of sound is an indication of the existence of ākāśa as that which is the substratum of the auditory power (_śruti_) which manifests the sounds of the same class in ākāśa. Such a manifestation of sound cannot be without such an auditory sense-power. Nor is such an auditory power a quality of pṛthivī (earth), etc., because it cannot be in its own self both the manifestor and the manifested (_vyahṅgya_ and _vyañjaka_), _Tattvavaiśāradī_, III. 41. It is the auditory power which manifests all sounds with the help of the ākāśa of the sense organ. The theory of the guṇas was accepted by many others outside the Sāṃkhya-Yoga circle and they also offered their opinions on the nature of the categories. There are thus other views prevalent about the genesis of the senses, to which it may be worth our while to pay some attention as we pass by. The sāttvika ego in generating the cognitive senses with limited powers for certain specified objects of sense only accounted for their developments from itself in accompaniment with the specific tanmātras. Thus sāttvika ego + sound potential (śabda-tanmātra) = sense of hearing. sāttvika ego + touch potential (śparś-tanmātra) = sense of touch. sāttvika ego + sight potential (śrūpa-tanmātra) = sense of vision. sāttvika ego + taste potential (vasa-tanmātra) = sense of taste. sāttvika ego + smell potential (gandha-tanmātra) = sense of smell. The conative sense of speech is developed in association with the sense of hearing; that of hand in association with the sense of touch; that of feet in association with the sense of vision; that of upastha in association with the sense of taste; that of pāyu in association with the sense of smell. Last of all, the manas is developed from the ego without any co-operating or accompanying cause.