Carbon is the basis of human life and iron of robot life. It becomes easy to speak of C/Fe when you wish express a culture that combines the best of the two on an equal but parallel basis.

Isaac Asimov's "Three Laws of Robotics"

A robot may not injure a human being or, through inaction, allow a human being to come to harm.
A robot must obey orders given it by human beings except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.

All normal life, Peter, consciously or otherwise, resents domination. If the domination is by an inferior, or by a supposed inferior, the resentment becomes stronger. Physically, and, to an extent, mentally, a robot—any robot—is superior to human beings. What makes him slavish, then? Only the First Law! Why, without it, the first order you tried to give a robot would result in your death. Unstable? What do you think?

After a long time, I decided that the Three Laws govern the manner in which my positronic pathways behave. At all times, under all stimuli the Laws constrain the direction and intensity of positronic flow along those pathways so that I always know what to do. Yet the level of knowledge of what to do is not always the same. There are times when my doing-as-I-must is under less constraint than at other times. I have always noticed that the lower the positronomotive potential, then the further removed from certainty is my decision as to which action to take. And the further removed from certainty I am, the nearer I am to ill being. To decide an action in a millisecond rather than a nanosecond produces a sensation I would not wish to be prolonged. What then, I thought to myself, madam, if I were utterly without Laws, as humans are? What if I could make no clear decision on what response to make to some given set of conditions? It would be unbearable and I do not willingly think of it.

A robot may not injure a human being, or, through inaction, allow a human being to come to harm. [The First Law of Robotics]

The Three Laws of Robotics:

1: A robot may not injure a human being or, through inaction, allow a human being to come to harm;

2: A robot must obey the orders given it by human beings except where such orders would conflict with the First Law;

3: A robot must protect its own existence as long as such protection does not conflict with the First or Second Law;

The Zeroth Law: A robot may not harm humanity, or, by inaction, allow humanity to come to harm.