So this is self-realization. We must understand our position. In the Purāṇas also, our minute particle identification . . . what is that? One ten-thousandth part of the top of the hair. We cannot see even the top of the hair. That you divide, keśāgra, keśa agra, the front portion of the hair. Keśāgra-śata-bhāgasya (Śvetāśvatara Upaniṣad 5.9). You divide into one hundred part. Śatadhā kalpitasya ca. Again take one part and divide into hundreds part. That is the dimension of the jīva. That small particle is there within the ant, the microbic germ, and he . . . that part is within the elephant. Jiva bhuta maha baho (BG 7.5). That is the dimension. So self-realization . . . self-realization means one must know his identity. That identity, that small particle, is there—within me, within you. Dehino 'smin yathā dehe (BG 2.13). Dehī is within the deha. But because it is so small, with our material eyes it is not possible to see. There is no such instrument that you can find out. Therefore on account of our inability to find it out, we say: "It is nirākāra," because we cannot calculate what is the ākāra, or what is the dimension. But the ākāra is there. The living entity has got full ākāra. If you have studied the small microbes . . . sometimes I see at night when I work, a small insect just like a full stop, it is walking. That means the whole physiological combination, anatomy, physiology, is there. But you cannot . . . you see just a like a full stop. So within that there is the soul. And within the elephant or big animal there is also the soul. The soul is there. Asmin dehe, dehino 'smin yathā dehe (BG 2.13). That is there.
So when we actually realize what we are, brahmānubhūti, then our life is successful. Now we are identifying with this body. So long we are identifying with this body, we are no better than the cats and dogs. Whatever knowledge you may have scientific knowledge, if you do not know yourself, then you are nothing but the animal.