Guy P. Harrison

author, skeptic, advocate for science and reason

“Harrison proves himself an excellent guide to reasonable thought in the 'swirling, festering ball of lies and madness' that is the modern world.”  —Publishers Weekly


“What would it take to create a world in which fantasy is not confused for fact and public policy is based on objective reality? I don't know for sure. But a good place to start would be for everyone on Earth to read this book."  —Neil deGrasse Tyson

“For all our vaunted intelligence, we human beings believe some really bizarre things. Guy P. Harrison takes us on a judicious, wide-ranging, and entertaining tour of the many dimensions of human mental weirdness, pointing out where we need to be particularly on guard against our poor decision-making processes.”   —Ian Tattersall, curator emeritus, American Museum of Natural History


“Rarely has a skeptic gone to battle against nonsense with such warmth and humor.”    Skeptic magazine




Buy the books here:



  • I will take part in an author panel and sign books at the inaugural San Diego Book Festival, August 2017.
  • Random House selected Think: Why you should question everything  for its First-Year Experience/CommonReads program, making it recommended reading for all first-year university students. I spoke and signed books at the recent 33rd annual First Year Experience Conference in California
  • San Diego's largest newspaper, The Union Tribune, named Think: Why you should question everything a "book of note"  
  • Canada's largest newspaper, The Toronto Star, praises Think in this article   
  • A Japanese translation  of Think: Why you should question everything is now on sale in Japan 
  • An Italian translation of my book, 50 Reasons People Give for Believing in a God has been published in Italy 
  • Korean and Belarusian translations of Think have been published



  • review  of Think published in Skeptical Inquirer    
  • "Bogus, Bunk, and B.S.", review  of 50 Popular Beliefs that People Think are True in Skeptic magazine
  • Skeptical Inquirer's review  of 50 Popular Beliefs That People Think are True


Interviews and talks 


Social media 

If you dwell in these worlds, connect with me at my Facebook author page  and on Twitter


More links

  • I am an "expert blogger" for Psychology Today. Read essays here 



Email:  guyfeedback [at] 


Guy P. Harrison (author)

C/O Prometheus Books

59 John Glenn Drive

Amherst, NY  14228 



A few words about thinking

One of the biggest mistakes we can make in life is to ignore or deny the possibility that we might be dead wrong about something that is very important to us.

Don’t do this!

Question everything. Embrace doubt. Second guess conclusions. Be humble; after all you could be wrong. You might be the first perfect person in all of history and prehistory who is incapable of being fooled by the mistakes, lies and delusions of others. But I doubt it. You might be the first ever to rise above and see through all the deceptive quirks, traps and biases that come standard with a human brain. But I doubt it.

What good is it to hold tight to a position against every challenge if that position is in error? The goal is not to avoid ever changing your mind. The goal is to be right, or as close to it as you can be. If you value wisdom and honesty then you ought to value skepticism. Wisdom is recognizing that you don’t know everything and can be fooled just like every other human who has ever lived. Wise people change their minds when evidence demands it. Honest people don’t pretend to know things that they don’t know.

This fundamental error in thinking crops up most often in politics and religion, of course. These two fertile fields of human thought, passion and silliness encourage if not demand that participants sacrifice their ability to think independently. This treasure is given away freely as rigid lines are drawn and feet set in cement. How can something of such value—the ability and the courage to think freely—be sacrificed by so many people with so little reluctance? Why the haste to become one more zombie in the mob? Why no remorse for the loss of so much humanity?

Do not undervalue your ability to think independently, to grow intellectually over a lifetime, and to always do your best to move closer to truth and reality. The warmth of mindless membership may be appealing at a glance but it’s fool’s gold.

Change. Grow. Improve. Think and be fully human.


—Guy P. Harrison