The System of the Vedanta according to Badarayana's Brahma-Sutras and Cankara's Commentary c8.s4.t2.4

c8.s4.t2.4

3. But if the soul is minute, it can only be at one place in the body; how comes it thus that it perceives throughout the body? For after a bath in the Ganges one feels the cold, and in summer one feels the heat all over one’s body (p. 653, 11).—We answer: just as a piece of sandalwood, even when it only touches the body at one spot, refreshes it all over (p. 654, 2) so the soul is only in one spot, *viz.*, as the Scripture teaches in many places, in the heart (p. 655, 5) and from here it feels throughout the body (p. 654, 3). This comes about by means of the sense of touch (*tvac*); the soul is connected with the sense of touch everywhere and the sense of touch pervades the whole body.¹¹¹ Or perhaps this power of the minute soul to feel throughout the body can be explained (p. 655, 10) from its spirituality (*caitanya-guṇa*) which here extends beyond the substance; just as we see in other cases in experience that the quality extends further than the substance, when *e.g.* the light of a jewel or of a lamp, which is only in one place in a room, extends from there through the whole room (p. 655, 11) or when we smell the scent of flowers without touching them (p. 656, 9). So too the Scripture teaches of the Soul, that though it is minute and dwells in the heart, by means of its quality of spirituality it penetrates the body (p. 658, 1) “to the hair and nails” (Kaush. 4, 20; cf. Bṛih. 1, 4, 7) and also in other passages (Kaush. 3, 6. Bṛih. 2, 1, 17) the soul is distinguished from the intellect (*prajñā, vijñānam*) with which it pervades the body (p. 658, 4).