Better by far to embrace the hard truth than a reassuring fable. If we crave some cosmic purpose, then let us find ourselves a worthy goal.

The truth may be puzzling. It may take some work to grapple with. It may be counterintuitive. It may contradict deeply held prejudices. It may not be consonant with what we desperately want to be true. But our preferences do not determine what's true.

One of the saddest lessons of history is this: If we’ve been bamboozled long enough, we tend to reject any evidence of the bamboozle. We’re no longer interested in finding out the truth. The bamboozle has captured us. It’s simply too painful to acknowledge, even to ourselves, that we’ve been taken. Once you give a charlatan power over you, you almost never get it back.

If we can't think for ourselves, if we're unwilling to question authority, then we're just putty in the hands of those in power.

Our perceptions are fallible. We sometimes see what isn't there. We are prey to optical illusions. Occasionally we hallucinate. We are error-prone.

In a lot of scientists, the ratio of wonder to skepticism declines in time. That may be connected with the fact that in some fields-mathematics, physics, some others-the great discoveries are almost entirely made by youngsters.

Extraordinary observations require extraordinary evidence to make them believable.