Spirit, on the contrary, may be defined as that which has its center in itself. It has not a unity outside itself, but has already found it; it exists in and with itself. Matter has its essence out of itself; Spirit is self-contained existence (Bei-sich-selbst-seyn). Now this is Freedom, exactly. For if I am dependent, my being is referred to something else which I am not; I cannot exist independently of something external. I am free, on the contrary, when my existence depends upon myself. This self-contained existence of Spirit is none other than self-consciousness consciousness of one's own being. Two things must be distinguished in consciousness; first, the fact that I know; secondly, what I know. In self-consciousness these are merged in one; for Spirit knows itself. It involves an appreciation of its own nature, as also an energy enabling it to realise itself; to make itself actually that which it is potentially.