聴覚内送説における音源定位問題

抄録

In debates over perception （pratyakṣa-）, a touchstone doctrine of each tradition of classical India is laid bare in the determination of the relationship between the faculty of the senses （indriya-） and its respective object. Besides the well-known controversy over whether a direct contact between a sense and the object is required, there is another demarcation concerning the theories of extramission and intromission, in which the former proposes a kind of emanation from the faculty of the senses toward its object, while the latter postulates that something arrives at the sense from an external object. One of the observed facts which clearly exposes the contrast between the two theories is the so-called sound source localization, which is the listener’s capability to determine the location of a sound source to some extent. This is a drawback for the theory of intromissive auditory perception, for it implies that all sound is heard in the listener’s ear orifice in a way similar to what happens when listening to music with earphones.

In fact, most of the philosophers belonging to the Vaiśeṣika and Mīmāṃsā schools, so far as they are considered in this paper, either simply explain the sound source localization as an invalid erroneous cognition （bhrānti-）, or just maintain silence on this topic. Among them, the Mīmāṃsaka polemicist Śālikanātha, who was allegedly the author of a commentary on the Vaiśeṣika treatise, exceptionally puts forward a more detailed analysis on the phenomenon in his Prakaraṇapañcikā. His attitude can be evaluated as an orientation toward critical thinking regarding natural science.