Have you ever thought that some cherished belief you hold might not be true? I have been thinking a great deal lately about the importance of believing responsibly. I am not always sure we realize that when we believe something, the stakes can be very high. The reason is because all of our beliefs can be truly consequential, particularly if the belief is in error.

I recently read about the practice of medicine back in the eighteenth century. In those days medical doctors were taught that the time-honored practice of bloodletting would help cure sick patients by removing bad or stagnant blood. Unchallenged for more than four thousand years, bloodletting was universally accepted as the most effective remedy for almost every disease. Although it seems archaic today, the prevailing theory before the circulatory system was fully understood was that blood could stagnate in the extremities. A buildup of bad blood was thought to cause all manner of maladies. The cure was to purge.

And everyone bought in. For centuries. Ancient cultures like the Mesopotamians and Egyptians. Hippocrates, the father of modern medicine, endorsed bloodletting as an effective treatment. As did Socrates and Plato. The Talmud, the central text of Rabbinic Judaism, specified certain days for bloodletting, while early Christian writings offered advice on which saints’ days were most favorable for the practice. Bloodletting was prescribed for everything from cholera to cancer, tetanus to tuberculosis, gout to gangrene. The more blood, the better. In 1799, George Washington, suffering from a throat infection, requested that his physician drain four pints of blood. Not surprisingly, shortly after the procedure, Washington died.

It wasn’t until the young scientist, Louis Pasteur discovered that it was germs, not bad blood that caused disease. This changed everything in the medical field. But you can imagine the shock of experienced doctors when they learned that their attempts to heal had actually harmed or even killed their patients. Yet this false belief had been embraced for thousands of years. That is the destructive power of believing what is false.

It is crucial for us to understand that truth has to be discovered, it cannot be invented. Truth is an objective reality that you seek to discover and understand. It never changes. It is not subject to debate or dialogue and it does not evolve over time.

I truly believe that if you want to live a healthy life that is in harmony with reality, you must seek to follow the truth wherever it may lead you.

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