" Just as there are those who accept every UFO report at face value, there are also those who dismiss the idea of alien visitation out of hand and with great passion. It is, they say, unnecessary to examine the evidence, and “unscientific” even to contemplate the issue. I once helped to organize a public debate at the annual meeting of the American Association for the Advancement of Science between proponent and opponent scientists of the proposition that some UFOs were spaceships; whereupon a distinguished physicist, whose judgment in many other matters I respected, threatened to sic the Vice President of the United States on me if I persisted in this madness. (Nevertheless, the debate was held and published, the issues were a little better clarified, and I did not hear from Spiro T. Agnew.) "

― Carl Sagan , The Demon-Haunted World: Science as a Candle in the Dark