When we're faced with an important decision, it's a good idea to perform due diligence: to collect information relevant to the situation and to forecast probable outcomes. However, the results of this analysis alone are never sufficient to produce the actual decision. This is because decision is an act of the will, and more closely aligned with emotion than with reason. The highest to which the rational mind can attain is the calculation of odds ratios associated with certain outcomes given specific assumptions. Understanding the limits of rational thought will help improve your decision-making process.