Good science is wise to the many forms of bias that can distort our assumptions, theories, experiments, observations and conclusions. We distort our beliefs and perceptions to avoid pain, fear, embarrassment, shame, anxiety, risk and responsibility. We distort our beliefs in order to hold on to money, power, ego, traditions, status, identity and stories. There are hundreds of ways in which our minds trick us into making errors. Our prejudices are often wrong. We attribute a person’s behaviour to their character rather than to the circumstances in which they find themselves. We assume that other people are thinking what we are thinking. We make many assumptions without even being aware of them. In a life or death situation, whatever helps us survive is true. In a tribal environment, the chief, elders and shaman tell us what to believe. In a power hierarchy, you must believe what the most powerful person or group tells you to believe. In an authoritarian bureaucracy or a fundamentalist group, the authorities will make sure you stick to the one right way of thinking, and woe betides you if you step out of line. In a scientific, entrepreneurial, business-oriented environment, the truth is evidence-based and pragmatic. If it works, or if it makes money, it is true for now. In the reductionist form of the scientific approach, your judgement, intuition, wisdom and instinct have no value. In the relativist, postmodern world, your truth is your truth and my truth is mine. We must rigorously root out all of these forms of bias as best we can in order to improve the quality of our beliefs and assertions of truth.