Two forms are there spiritual. One is the Supreme Lord's form, virat-rupa, mahato mahiyan, and our form, anor aniyan, lesser than the atom. That is stated in the Katha Upaniсad. Anor aniyan mahato mahiyan atmasya jantor nihito guhayam. Nihito guhayam, guhayam means in the heart. Both of them are there. Now find out modern science. Both the soul and the Supersoul, they are situated within the heart. Isvarah sarva-bhutanаm hrd-dese [Bg. 18.61]. It is not said that "Anywhere in the body it is sitting." No. Hrd-dese, in the heart. And actually, by medical science, the heart is the center of all activities of the body, office. And the brain is the manager. The director is there, Krsna. He says also in another place, sarvasya caham hrdi sannivisto. Everything is clear. Sarvasya caham hrdi sannivisto, "I am sitting in everyone's heart." Find out God, find out Krsna. In several places, all Vedic literature, guhayam. Guhayam means in the heart. Sarvasya caham hrdi sannivisto mattah smrtir jnanam apohanam ca [Bg. 15.15]. The supreme director, Krsna, is sitting there, and He is directing.
Lecture on Bhagavad-gita 2.21-22, London, 20 August, 1973