Eros: one of the two basic sources of all the drives. Eros, whose name comes from the Greek god of love, is the principle of life; it binds together and is most clearly seen in love. Its drives tend to be more plastic and displaceable than those of its opponent, Thanatos, the death drive.
Thanatos: this drive represents the organic need to return to lifelessness and stasis, the ultimate calm of lifeless non-conflict. Freud traced all aggressive and destructive activity to this notion.