During my senior year of college, I was privileged to hear a presentation given by the great historian Thomas Kuhn. He had written one of the most influential books of science in the twentieth century. The book was titled, The Structure of Scientific Revolutions. It was about the progress of scientific knowledge. The book focused on the great advances of sciences through which he called “revolutions” which are so often hindered by holding on to old beliefs.

I think it is easy for us to assume that scientists are immune to the influence of their own beliefs and biases as they do research. We have this presumption that scientists are dispassionate and unbiased individuals who are committed to the truth and always simply report the facts.

Kuhn’s book points out this fallacy, as his research into the history of science reveals that scientists are clearly not objective. He provides dozens of historical cases that prove researchers are far from being neutral and unbiased, particularly in testing and evaluating results. He makes it clear that scientists have a real tendency to hold on tenaciously to their theories, even though they face contradicting data.

The late Dr. Herbert Schlossberg, a leading historian and scholar, made this observation:

“Thomas Kuhn concluded that at a given time any scientific community will always have in its structure an element that is more will than intellect, a product of personal history.”

Back in August of 2014, David Brooks wrote an article in The New York Times titled “The Mental Virtues.” He refers to the book Intellectual Virtues by Robert Roberts and Jay Wood. In their book, they speak of the importance of having intellectual cour­age—the willingness to hold unpopular views. In the article, Brooks then makes reference to Kuhn:

“Thomas Kuhn pointed out that scientists often simply ignore facts that don’t fit their existing paradigms, but an intellec­tually courageous person is willing to look at things that are surprisingly hard to look at.”

One of the most prominent astronomers in the last century was Dr. Robert Jastrow. He received his PhD from Columbia University and then worked for a number of years at NASA, un­til taking a position at Dartmouth, where he taught for 11 years.

Jastrow was agnostic, but spoke of willful blindness in his book, God and the Astronomers. He described how scientists react when they encounter evidence they do not like. He says:

“Their reactions provide an interesting demonstration of the response of the scientific mind—supposedly a very objective mind—when evidence uncovered by science itself leads to a conflict with the articles of faith in our professions. It turns out that the scientist behaves the way the rest of us do when our beliefs are in conflict with the evidence. We become ir­ritated, we pretend the conflict does not exist, or we paper it over with meaningless phrases.”

This is why, later in life, Einstein made a very important observation about science. He said, “Most people think it is the intellect which makes a great scientist. They are wrong. It is their character.” Einstein recognized that the key to being a great scientist is to follow the evidence and the truth, wherever it leads you.

Richard E Simmons III is the founder and Executive Director of The Center for Executive Leadership and a best-selling author.