What is reason? The 2500 year old history of reason is a prolonged search for the definition of reason. The 18th century was called the Age of Reason, but it’s not clear even in our times how reason operates, what its limitations are, and what its relationship is to man's emotions, passions, and instinct. The philosophies are incapable of investigating reason because a focus on reason has the paradoxical effect of driving a philosophy towards rationalization and dogmatism. In the last 300 years, the word “reason” has become a sepulcher that holds the remains of the dead philosophies which, during their short lifetime, dared to overreach their aspirations and call themselves the “philosophy of reason."