Carl Sagan and the Psychology of Intellectual Humility
Understanding the Psychology of Denial
Carl Sagan was one of the twentieth century’s most remarkable polymaths—a scientist, philosopher, writer, and communicator who seemed equally comfortable discussing the vast cosmos or the intimate workings of human cognition. Born in Brooklyn, New York in 1934, Sagan grew up in a working-class Jewish family. His mother, Rachel, nurtured his curiosity. His father, Sam, worked as a theater manager. His childhood in 1940s New York profoundly shaped his worldview. Young Carl would wander through the American Museum of Natural History, mesmerized by the exhibits. This sense of wonder at the natural world never left him.
He earned his Ph.D. in astronomy and astrophysics from the University of Chicago in 1960. His intellectual reach extended far beyond conventional astronomy into psychology, philosophy, history, and literature. Throughout his career, Sagan held positions at prestigious institutions, including Cornell University. He spent most of his professional life there as director of the Laboratory for Planetary Studies. What distinguished him from many scientific peers was his unwavering commitment to public education. He believed that science belonged to everyone, not merely to specialists.
Sagan’s lifelong obsession with epistemology directly inspired this quote. Epistemology is the philosophy of how we know what we know. More importantly, it explores how we consistently fail to know things accurately. This statement likely derives from Sagan’s work in the 1970s and 1980s. He actively wrote and spoke about cognitive biases and human self-deception. He also discussed what might be called intellectual virtue. During this period, Sagan engaged deeply with the budding field of cognitive psychology. He studied researchers investigating how humans process information. He learned how people justify existing beliefs.
He explored how people resist contradictory evidence. Sagan became fascinated by what psychologists call “confirmation bias”—our tendency to seek out information that confirms what we already believe. We dismiss information that contradicts our worldview. Sagan understood that this was not a character flaw restricted to the unintelligent or intellectually lazy. Rather, it was a universal human tendency. Our neurology embedded it in us. Our social environments reinforced it. He was particularly concerned with how this bias appeared in science itself. Even trained researchers could become attached to theories or data interpretations that confirmed their previous work.
It’s sometimes easier to reject strong evidence than to admit that we’ve been wrong
What made Sagan unique among scientists was his genuine curiosity about why humans—including scientists—consistently make these errors. Rather than dismissing the tendency to reject strong evidence as mere stupidity or stubbornness, he recognized it as a fascinating window into how human consciousness operates. Sagan pursued a lesser-known aspect of his career: serious engagement with the paranormal and pseudoscience. He did this not to promote these ideas, but to understand them. In the 1970s, he actively investigated claims of extrasensory perception and other paranormal phenomena at Stanford University with physicist Harold Puthoff. Though he remained skeptical, Sagan approached these investigations with genuine intellectual humility. He recognized that his skepticism was not absolute certainty.
Rather, it was a provisional stance based on available evidence. This experience deeply influenced his understanding of how intelligent people can become convinced of false things. It also showed him how genuine scientific openness requires acknowledging that our current understanding might be incomplete or wrong. He came to understand that the human capacity for self-deception was not something to mock. Rather, he saw it as something to study and understand. Only through understanding it could we hope to counteract it.
Using this self-knowledge for personal growth
The broader context of Sagan’s life during the Cold War illuminates this quote. Sagan lived through an era when powerful nations were willing to wage war. They based these wars on ideological commitments that people had become deeply psychologically invested in defending. He watched nations cling to theories about nuclear deterrence. They clung to ideas about the feasibility of nuclear war. They held onto various military strategies even when evidence mounted that these theories were fundamentally flawed or morally catastrophic.
He saw religious fundamentalists reject scientific evidence about evolution and cosmology. But he also saw scientists dismiss legitimate questions or evidence because those questions challenged their career-long commitments. This was not abstract philosophy to Sagan; it was a matter of human survival. In this context, his insight about the difficulty of admitting we’ve been wrong took on urgent ethical dimensions. If humans could not learn to acknowledge their errors, Sagan feared we would not survive our own technological power. This concern directly informed his later work on nuclear winter and his activism around reducing nuclear arsenals.
The quote also resonates with Sagan’s broader philosophical framework concerning what he called “baloney detection” or the development of critical thinking skills. In his book “The Demon-Haunted World,” published near the end of his life in 1996, Sagan developed this idea most fully. He created what he called a “baloney detection kit”—a set of intellectual tools designed to help people distinguish reliable knowledge from unreliable claims. Central to this kit was the recognition that saying “I was wrong” is actually a sign of intellectual strength, not weakness. For Sagan, the capacity to revise one’s beliefs in light of new evidence was not a failure.
Rather, it was the very heart of the scientific method and of rational thinking more broadly. This stands in sharp contrast to much of human behavior, where admitting error is often treated as a social humiliation or a blow to one’s status. Sagan argued that we should invert this social calculus. The willingness to be wrong