Postel's Law: What the Internet Teaches Us About Life

Ask an Internet geek why the highly decentralized protocols work as well as they do, and the the answer will probably be some version of what's known as Postel's Law. Although Jon Postel himself was less concise, it's most often stated simply as:

"Be conservative in what you send; be liberal in what you accept."

In protocol design, this a recipe for robustness. Each implementor is exhorted to follow the standards as precisely as possible in what his code sends out over the net, but to be more forgiving and tolerant in trying to interpret what his code receives. As long as most implementors follow this philosophy, the open Internet protocols work, despite countless small mistakes in various sending systems.

The Internet's success is nothing short of astonishing. Few human constructions have even a fraction of its complexity, scale, and reliability. It's not unreasonable, therefore, to ask whether Postel's Law might be useful beyond its intended domain of network protocol design. In fact, for some time, it has been one of the basic principles by which I've tried to live my life.

The essence of the law is a mandate of individual responsibility. Each implementor is to hold himself to the highest standard (of compliance with the protocol specification), while being as forgiving as possible of the failures of others to do the same. Each is encouraged to strive for perfection in his own actions, while expecting far less from others.

The real world, of course, works nothing like this. People struggle for advantage over each other, cutting corners, casting blame, and generally behaving as individuals with no responsibility to any larger social organization. They hide their own misdeeds while piously decrying the failings of others. In short, they expect more from others than from themselves, holding others to a standard they are themselves failing to meet.

What would it mean to live in a world guided by Postel's Law? It would mean holding oneself to the highest standards, while striving to be as forgiving as possible of the failings of others. It would mean being more concerned about one's own actions than those of others, and more concerned with the welfare of one's society than the wealth of one's self.

Consider the hottest of hot-button issues: If you believe that abortion is murder, you of course would not get an abortion your self. You might also work to provide alternatives to anyone considering abortion, with help getting through the pregnancy and giving the baby a life. But you would strive to be as tolerant as you could of people who made what you considered the wrong choice -- of those who, for whatever reason, do not feel they can uphold the same standards as you.

In a world ruled by Postel's Law, people would still disagree. But they would focus on their own behavior, on their own struggle -- never perfect, for human beings -- to live up to their own ideals. And they would view others with the compassion of knowing no one ever lives up to every ideal. Some people would remain beyond the pale by any standards -- violent criminals, repeat offenders -- but most people who did something wrong would be treated with education and encouragement to do better.

Unfortunately, we don't live in such a world. But we can live in such a mindset. We can try to behave, in our own limited spheres of influence, as correctly as we can, while being as compassionate as we can about others' failures. That's what I'm trying to do, and I encourage you to do the same.

But I'll do my best to be accepting and understanding if you don't.