In formal logic a contradiction is the signal of defeat but in the evolution of real knowledge it marks the first step in progress toward a victory.

From a reality perspective I'm sure part of that is true but this is the largest blackout in U.S. history. If that is not a signal that we have got a problem that needs to be fixed I don't know what is.

Jewelry and pins have been worn throughout history as symbols of power sending messages. Interestingly enough it was mostly men who wore the jewelry in various times and obviously crowns were part of signals that were being sent throughout history by people of rank.

This change to a higher phase of alert is a signal to governments to ministries of health and other ministries to the pharmaceutical industry and the business community that certain actions now should be undertaken with increased urgency and at an accelerated pace.

The way that organizations and organisms anticipate the future is by taking signals from the past most the time.

For much of the female half of the world food is the first signal of our inferiority. It lets us know that our own families may consider female bodies to be less deserving less needy less valuable.

I'm on the Sensa diet. It's a little magic powder based on Dr. Hirsh's clinical trials and studies and it basically signals the brain that you're full through smellology.

The cult of the individual is killing us. I think Twitter signals the death of western civilisation but people have been saying that since Demosthenes.

And it's here and it's ready and we can really revolutionize the way we educate our children with tablet computers and I'm committed to doing whatever I can to speaking to whomever I can to send this signal - to pound this message home. Now is the time.

If beauty isn't genius it usually signals at least a high level of animal cunning.