Aitareya-Aranyaka: Second Aranyaka, Third Adhyâya, Second Khanda
1. He who knows the gradual development of the self in him (the man conceived as the uktha), obtains himself more development.
2. There are herbs and trees and all that is animated, and he knows the self gradually developing in them. For in herbs and trees sap only is seen, but thought (kitta) in animated beings.
3. Among animated beings again the self develops gradually, for in some sap (blood) is seen (as well as thought), but in others thought is not seen.
4. And in man again the self develops gradually, for he is most endowed with knowledge. He saying what he has known, he sees what he has known. He knows what is to happen tomorrow, he knows heaven and hell. By means of the mortal he desires the immortal—thus is he endowed.
5. With regard to the other animals hunger and thirst only are a kind of understanding. But they do not say what they have known, nor do they see what they have known. They do not know what is to happen tomorrow, nor heaven and hell. They go so far and no further, for they are born according to their knowledge (in a former life).