In this, his magnum opus one of the world’s best known skeptics and critical thinkers Dr. Michael Shermer—founding publisher of Skeptic magazine and perennial monthly columnist (“Skeptic”) for Scientific American—presents his comprehensive theory on how beliefs are born, formed, nourished, reinforced, challenged, changed, and extinguished. This book synthesizes Dr. Shermer’s 30 years of research to answer the questions of how and why we believe what we do in all aspects of our lives, from our suspicions and superstitions to our politics, economics, and social beliefs. In this book Dr. Shermer is interested in more than just why people believe weird things, or why people believe this or that claim, but in why people believe anything at all. His thesis is straightforward:

We form our beliefs for a variety of subjective, personal, emotional, and psychological reasons in the context of environments created by family, friends, colleagues, culture, and society at large; after forming our beliefs we then defend, justify, and rationalize them with a host of intellectual reasons, cogent arguments, and rational explanations. Beliefs come first, explanations for beliefs follow.

Dr. Shermer also provides the neuroscience behind our beliefs. The brain is a belief engine. From sensory data flowing in through the senses the brain naturally begins to look for and find patterns, and then infuses those patterns with meaning. The first process Dr. Shermer calls patternicity: the tendency to find meaningful patterns in both meaningful and meaningless data. The second process he calls agenticity: the tendency to infuse patterns with meaning, intention, and agency.

We can’t help believing. Our brains evolved to connect the dots of our world into meaningful patterns that explain why things happen. These meaningful patterns become beliefs. Once beliefs are formed the brain begins to look for and find confirmatory evidence in support of those beliefs, which adds an emotional boost of further confidence in the beliefs and thereby accelerates the process of reinforcing them, and round and round the process goes in a positive feedback loop of belief confirmation. Dr. Shermer outlines the numerous cognitive tools our brains engage to reinforce our beliefs as truths and to insure that we are always right.

Interlaced with his theory of belief, Dr. Shermer provides countless real-world examples of belief from all realms of life, and in the end he demonstrates why science is the best tool ever devised to determine whether or not a belief matches reality.