Even the best models of the world are imperfect. This insight is important to remember if we want to learn how to make decisions and take action on a daily basis.

For example, consider the work of Albert Einstein.

During the ten year period from 1905 to 1915, Einstein developed the general theory of relativity, which is one of the most important ideas in modern physics. Einstein's theory has held up remarkably well over time. For example, general relativity predicted the existence of gravitational waves, which scientists finally confirmed in 2015—a full 100 years after Einstein originally wrote it down.

However, even Einstein's best ideas were imperfect. While general relativity explains how the universe works in many situations, it breaks down in certain extreme cases (like inside black holes).

All Models Are Wrong, Some are Useful

In 1976, a British statistician named George Box wrote the famous line, “All models are wrong, some are useful.” 1

His point was that we should focus more on whether something can be applied to everyday life in a useful manner rather than debating endlessly if an answer is correct in all cases. As historian Yuval Noah Harari puts it, “Scientists generally agree that no theory is 100 percent correct. Thus, the real test of knowledge is not truth, but utility. Science gives us power. The more useful that power, the better the science.”

Even Einstein's work was not perfect in all cases, but it has been incredibly useful—not just for increasing our understanding of the world, but also for practical purposes. For example, the Global Positioning Systems (GPS) used in your phone and in your car must take the effects of relativity into account to deliver accurate directions. Without general relativity, our navigation systems wouldn’t be accurate.

How to Make Decisions in an Imperfect World

What steps can we take to make decisions, given that no single way of looking at the world is accurate in all situations?

One approach is to develop a broad collection of frameworks for thinking about the world. Some experts refer to each framework as a “mental model.” Each mental model is a way of thinking about the world. The more mental models you have, the more tools you have in your thinking toolbox to make decisions.

For example, here are three ways of thinking about productivity:

The 2-Minute Rule: If something takes less than two minutes, do it now. The goal of this rule is to help you stop procrastinating and take action. The Ivy Lee Method: Create a to-do list by writing down the six most important things you need to accomplish tomorrow, prioritizing those items, and working on them in order. The goal of this method is to help you work on the most important things first. The Seinfeld Strategy: Pick a new habit and draw an X on the calendar for each day you stick with the behavior. The goal of this method is to help you maintain consistency and keep your streak of good behavior alive.

Are any of these models perfect? Of course not. But if you combine them, then you have a strategy that can help you take action right now (The 2-Minute Rule), a strategy that can help you plan your day more effectively (The Ivy Lee Method), and a strategy that can help you maintain consistency in the long-run (The Seinfeld Strategy).

You need a collection of mental models because no single framework can work in every situation.

Doing the Best We Can With What We Have

Accepting that all models are wrong in certain instances is not a license to ignore the facts. As a society, we should search for better answers, look for evidence, and strive to increase the accuracy of our knowledge.

At the same time, there is a common peril on the other end of the spectrum. Too many people waste time debating if something is perfectly correct, when they should be focusing on if it is practically useful.

We live in a world filled with uncertainty, but we still need to get things done and make decisions. It is our responsibility to develop a way of thinking about the world that generally fits the facts we have, but to not get so gummed up thinking about things that we never actually do anything. As Harvard professor Daniel Gilbert puts it, “The world doesn’t have the luxury of waiting for complete answers before it takes action.”

Impartial answers are the best we have. Focus on what is practical and take action. All models are wrong under some circumstances, but the important thing is if they are generally useful.