And that anything can be anything in the abstract world inside his computer. Risk and Decisions Risk is a concept that I have difficulty with. The concept of risk is part of Decision Theory, but doesn't fit with my simple conceptualization of uncertainty. In the simplest sense, Decision Theory is the study of choice under conditions of uncertainty. Since the complexity of systems makes the future inherently unknowable, we have to decide based on belief about the future.
Probability is a way to quantify belief about the likelihood of future events.
One should choose based upon the average value of the choice given the likelihood of various outcomes and their associated utility of value to the person or group making the decision. Its the chance of unwanted, uncertain events. Generally bad events. We don't talk about the risk of winning the lottery only the risk of crashing your car. Or your motorcycle.