You determine your nature by you own free will,

"I have given you, O Adam, no fixed abode, and no visage of your own, nor any special gift, in order that whatever place or aspect or talents you yourself will have desired, you may have and possess them wholly in accord with your desire and your own decision. Other species are confined to a prescribed nature, under laws of my making. No limits have been imposed upon you, however; you determine your nature by you own free will, in the hands of which I have placed you. I have placed you at the world’s very center, that you may the better behold from this point whatever is in the world. And I have made you neither celestial nor terrestrial, neither mortal nor immortal, so that, like a free and able sculptor and painter of yourself, you may mold yourself wholly in the form of your choice"

Pico Della Mirandola’s "Oratio de hominis dignitate"