John Littlewood's law of miracles states that we can expect "miracles" to happen often.
If we see and hear things happening at a rate of one per second, the total number of events that happen to us in a month will be about a million. The chance of a miracle is about one per million events. Therefore we should expect about one miracle every month.

“For every PhD, there is an equal and opposite PhD.” 

In law and public policy, for every qualified expert witness, there is an expert witness that will come to the opposite conclusion.

"The amount of energy needed to refute bullsh*t is an order of magnitude bigger than to produce it."

Albert Brandolini's law acknowledges four truths:

• People don't like to admit when they don't understand something. When they are confronted with nonsense, they will rather agree than admit they don't understand.
• In law, the burden of proof lies with the prosecution (You often can't prove something didn't happen).
• Bad commentary gives readers a cover to hide their own biases and prejudices.
• Publishing an opinion has become very easy in the last two decades.

When a measure becomes a target, it stops being a good measure.
Charles Goodhart is an economist who recognized that once you set a new policy target, the authority involved has his reputation attached to meet that target successfully and may neglect or adjust his behavior and procedures for that target.

Dollo's law of irreversibility states that an organism can't re-evolve to a former state. The path that led to its former state was so intricate that it is impossible to retrace that exact path.

This law affects businesses and brands. Some things are hard to build, and once lost, will likely never be regained.

Work expands to fill the time available for its completion.
This can also be applied to other ideas. For instance, expenses expand to fill an income, or data can expand to fill a given level of storage.

“Communication usually fails, except by accident.”

Osmo Wiio, a Finnish journalist, also made other laws of communication, such as:

• “If a message can be understood in different ways, it will be understood in just that way which does the most harm.”
• “In mass communication, the important thing is not how things are but how they seem to be.”

In a dispute, the intensity of emotions is inversely related to the value of the issues at stake.

When the stakes are actually high, people are willing to put their differences aside for a common cause.

No scientific discovery is named after its original discoverer.

Discoveries are most often the result of a combination of existing discoveries that solve a problem with an old invention.

The famous person is often the one who communicates an idea the best, not whose idea is the best.

Assuming the familiar is the best.

You are in danger of thinking your own ideas are better because they are familiar. Your mind will always give your ideas more credit over other ideas that are better, but harder to explain.

Problems in complex systems rarely have one cause.
Doctor John Hickam observed that a patient is likely to have a few common problems and rarely just one. To try and get to the one underlying cause is likely to be a misdiagnosis.