“The absence of evidence is not the evidence of absence.”

“My view is that if there is no evidence for it, then forget about it. An agnostic is somebody who doesn’t believe in something until there is evidence for it, so I’m agnostic.”

“An atheist is someone who is certain that God doesn't exist, someone who has compelling evidence against the existence of God. I know of no such compelling evidence.”

“Extraordinary claims require extraordinary evidence.”

“Now, what's the difference between an invisible, incorporeal, floating dragon who spits heatless fire and no dragon at all? If there's no way to disprove my contention, no conceivable experiment that would count against it, what does it mean to say that my dragon exists? Your inability to invalidate my hypothesis is not at all the same thing as proving it true. Claims that cannot be tested, assertions immune to disproof are veridically worthless, whatever value they may have in inspiring us or in exciting our sense of wonder. What I'm asking you to do comes down to believing, in the absence of evidence, on my say-so.”

“You can't convince a believer of anything; for their belief is not based on evidence, it's based on a deep seated need to believe”

“In college, in the early 1950s, I began to learn a little about how science works, the secrets of its great success, how rigorous the standards of evidence must be if we are really to know something is true, how many false starts and dead ends have plagued human thinking, how our biases can colour our interpretation of evidence, and how often belief systems widely held and supported by the political, religious and academic hierarchies turn out to be not just slightly in error, but grotesquely wrong.”