Your mental models influence how you think about things and how you act. For example, a long time ago the primary model in medicine was that the body contained four basic fluids, known as humors. Humors were related to different temperaments, and imbalances between them caused different diseases:

Humorism, image by Tom Lemmens via [Wikimedia](

Humorism, image by Tom Lemmens via Wikimedia.

This model influenced medical practice for more than 2,000 years. If you were a doctor trying to save a dying patient during those times, your approach to treatment would be influenced by this model. You wouldn’t question it. In the 19th Century, advances in medical research did away with humorism. The model was disproven and abandoned as new knowledge came in.

When trying to make important decisions, I examine the models that influence my thinking. There are many: models about interpersonal relationships, models about incentives, models about technology, etc. These models are imperfect by definition. (Norbert Wiener: “The best material model of a cat is another, or preferably the same, cat.”) Some may reflect reality better than others, which is to say, some are more useful than others. (By useful I mean they result in better predictions about the outcomes of decisions. Note usefulness is only evident in retrospect.) By default, I assume these models are incomplete, especially when dealing with messy situations.

The only way to refine the models is through knowledge, which you must consciously search out. If you don’t understand something, you ask questions; if the questions aren’t forthcoming — or in more extreme cases, are actively rejected — that also adds a data point. Little by little you build a more complete model, one informed by what you’re observing in the world. This model should be built on observation and contemplation, not just hearsay. If your model relies on authority, you must be sure you trust that authority. (This is yet another important model that influences behavior. How do you know people know what they say they know?)

The ultimate authority to be suspicious of is ourselves. We run the risk of becoming attached to our models, closing ourselves off from new information that might shake our foundations. Thus, the importance of being open-minded. Open minded, with eyes wide open. Letting new knowledge in, with the expectation that all models are incomplete and up for revision as new information arrives.