Sometimes we find a small full-stop-like creature moving on the page of the . . . on a leaf of the book. You cannot see it, but it is moving. That small creature also has got heart. But is there any scientist to find out how he is moving, how he has got leg, how he has got hands, how he has got . . .? Any anatomy, is there any anatomy or physiological science to test? Here is our Dr. Mukerjee, sitting. Can you find out the heart in that small particle-like animal? It is not possible. But there is. But there is—otherwise, how Kṛṣṇa says sarva-bhūtānām, "all living entities"?
So our so-called scientific advancement always remains indefinitely imperfect, because it is not possible to understand the whole thing as it is. But we can understand from Bhagavad-gītā that there is heart. Now if you go to the laboratory to find out where is the heart of the small creatures, you have no capacity, neither you have instrument. No. Therefore your knowledge will always be imperfect, because this process of acquiring knowledge is always imperfect. But this knowledge, as we hear from Bhagavad-gītā that there is heart in every living entity, this is perfect knowledge.
Therefore there are two kinds of processes to receive knowledge. The Vedic process says avaroha-panthā, descending process. And the material process is āroha-panthā, ascending process, research. This is āroha-panthā, find out whether this, what is this, what is this, neti, neti, neti, neti, analysis, dissection, and so many. This is called āroha-panthā, trying to ascend by dint of one's material knowledge.
Then spiritual knowledge, you cannot have perfect knowledge . . . why spiritual knowledge? Even material knowledge. Now there are so many attempts to go to the moon planet. They are trying to go there by so many ascending processes, Sputnik, airplanes and so many things. Still, we do not know what is this planet?
But you read Bhagavad-gītā or Śrīmad-Bhāgavatam, you understand immediately what is this moon planet.