If you take the word in a real sense, the survival of the fittest, one who has understood that he is not this body, he is spirit soul, he is fit to survive

Expressions researched:
"one who has understood that he is not this body, he is spirit soul, he is fit to survive"

Srimad-Bhagavatam Lectures

"Survival of the fittest," they say. Nobody will survive. So there is no question.

Lecture on SB 6.1.25 -- Chicago, July 9, 1975:

So our endeavor should be, instead of being attached to this false enjoyment like cats and dogs, like the animal is running after the false water, the human life is meant for understanding that "The animal is running after false water. Why I shall go there? I am not animal." That is human life. If one, like the cats and dogs and deer, animal, runs after the false water and he dies, struggle for existence... "Survival of the fittest," they say. Nobody will survive. So there is no question. If you take the word in a real sense, the survival of the fittest, one who has understood that he is not this body, he is spirit soul, he is fit to survive. Otherwise, bhūtvā bhūtvā pralīyate (BG 8.19), you will run after this false thing, and this body will be finished, and again you will have to accept another body, and again you will run after, bhūtvā bhūtvā pralīyate (BG 8.19). This is going on. After false thing. Therefore the śāstra says that this human form of life is not meant for running after this false thing. They must understand what is reality.