Freud divided mental activity into the 3 roles of the id, ego and super-ego:

Quote Originally Posted by wikipedia
According to this model of the psyche, the id is the set of uncoordinated instinctual trends; the super-ego plays the critical and moralizing role; and the ego is the organized, realistic part that mediates between the desires of the id and the super-ego.
This seems like a useful model. There is a battle between what one wants at any particular moment, and what would be considered morally proper when taking the larger picture into account.

We are largely unaware of where the particular factors that play into our decision making come from, but rather are given them by our mind, and it is our task to make sense of them to find the proper course of action (i.e. ethics as taking into account morality as well as other factors to produce action).

A third factor that acts on the ego is reality. Some say that we should transcend both our desires and our morality and do what corresponds to reality. Is there truth to this?