The ancient Stoic philosophers like Marcus Aurelius, Seneca, and Epictetus regularly conducted an exercise known as a premeditatio malorum, which translates to a “premeditation of evils.”The goal of this exercise was to envision the negative things that could happen in life. For example, the Stoics would imagine what it would be like to lose their job and become homeless or to suffer an injury and become paralyzed or to have their reputation ruined and lose their status in society.The Stoics believed that by imagining the worst case scenario ahead of time, they could overcome their fears of negative experiences and make better plans to prevent them. While most people were focused on how they could achieve success, the Stoics also considered how they would manage failure. What would things look like if everything went wrong tomorrow? And what does this tell us about how we should prepare today?I first heard this exercise coined “Fear setting” by Tim Ferris. This exercise can also be called “Inversion”.When I first learned of it, I didn’t realize how powerful it could be. As I have studied it more, I have begun to realize that inversion is a rare and crucial skill that nearly all great thinkers use to their advantage. It’s become such a staple of my thinking that in our weekly and monthly meetings, my training team and I will regularly perform this exercise. We spend time each meeting projecting this exercise out – imagining and assuming these scenarios for clients of ours so that we can present solutions to problems before they even happen.Success is Overvalued. Avoiding Failure Matters More.This type of inverse logic can be extended to many areas of life. For example, ambitious young people are often focused on how to achieve success. But billionaire investor Charlie Munger encourages them to consider the inverse of success instead.“What do you want to avoid?” he asks. “Such an easy answer: sloth and unreliability. If you’re unreliable it doesn’t matter what your virtues are. You’re going to crater immediately. Doing what you have faithfully engaged to do should be an automatic part of your conduct. You want to avoid sloth and unreliability.” Avoiding mistakes is an under-appreciated way to improve. In most jobs, you can enjoy some degree of success simply by being proactive and reliable—even if you are not particularly smart, fast, or talented in a given area. Sometimes it is more important to consider why people fail in life than why they succeed.Consider the OppositeInversion is counterintuitive. It is not obvious to spend time thinking about the opposite of what you want.And yet inversion is a key tool of many great thinkers. Stoic practitioners visualize negative outcomes. Groundbreaking artists invert the status quo. Effective leaders avoid the mistakes that prevent success just as much as they chase the skills that accelerate it.Inversion can be particularly useful for challenging your own beliefs. It forces you to treat your decisions like a court of law. In court, the jury has to listen to both sides of the argument before making up their mind. Inversion helps you do something similar. What if the evidence disconfirmed what you believe? What if you tried to destroy the views that you cherish? Inversion prevents you from making up your mind after your first conclusion. It is a way to counteract the gravitational pull of confirmation bias.Inversion is an essential skill for leading a logical and rational life. It allows you to step outside your normal patterns of thought and see situations from a different angle. Whatever problem you are facing, always consider the opposite side of things.