In the Elisabethian times, it was common belief that all living creatures where part of the "chain of being".

The man

In this great cosmic hierarchy the man was placed in the middle, with God and the angels above who represented reason and spirit, and the animals and plants below as a symbol of passion and matter.

Mans situation in the middle of this hierarchy put him in a great conflict between his reason and his passion. Because of the fall of man, he was always in danger of descending to a more animalistic level and could never move up to the angels. Therefore man had to know himself and that was one of the finest virtues.

In the Elizabethan world view it was a common belief that man had free will.
To work one’s way up the chain of being, one had to have knowledge about oneself, this was essential for man, if he wished to save himself from his sins. He had to make the right choice, of reason and not of passion if he wished to redeem himself. It's unquestionable that Shakespeare knew about these values, because it was the convention of his time.

Editors - Simon and Adam