Via Negativa: Why Subtraction beats Addition

Nutrition advice works best when it emphasizes what not to eat rather than what to eat. Nutrition is not about finding the best supplements and eating the perfect combination of protein and carbs. Rather, nutrition and diet works best through subtraction. Take out what is bad and what you're left with is good enough. For example, one of the most popular diets, the Mediterranean diet, starts first with what to cut out.

As much as you can, cut out sugars, processed and red meats, enriched grains, and most things man made (if there are a lot of ingredients on the label you don't understand). What you're left with is the good stuff. We don't know exactly how good these are, but we know that they're not bad, and this is the most important. Proving that something negatively impacts you is more useful than proving that it positively impacts you. This is the essence of the negative way or in Latin - via negativa. Antifragile by Nassim Taleb devotes an entire book to via negativa, and this post is largely inspired by this book.

We learn more from what we know is bad. As Taleb puts it, "The greatest - and most robust - contribution to knowledge consists in removing what we think is wrong - subtractive epistemology." Subtractive knowledge is more valuable than positive knowledge. "So knowledge grows by subtraction much more than by addition - give that what we know today might turn out to be wrong, but what we know to be wrong cannot turn out to be right, at least not easily."

This concept is explained further by our history with cigarettes. We know today that people don't smoke a cigarette and ask about the health benefits. However, in the 1960s, The Mad Men came up with "positive knowledge" to support cigarette smoking. In fact, they weren’t lying. For example, "your doctor smokes Camels, cigarettes help you to lose weight, and it increases your focus." These ads may have convinced people to smoke cigarettes (or give an excuse not to quit). However, we must learn to rely more on a via negativa approach. We should have been very careful to add cigarettes to our lives until we were certain that it wasn’t bad for us. Learning that cigarettes cause lung cancer is the negative knowledge we need to cut it out of our lives. “What we know to be wrong cannot turn out to be right.”

Via negativa is a risk based approach. In a world of uncertainty, we should be extra cautious about things that have not been proven. In order for things to be proven through negative knowledge, they must stand the test of time. The longer something has been around without evidence that it’s harmful, the higher the chance it’s not bad for you. We’re very confident that apples are not bad for you. However, had you started smoking cigarettes in the 1940s when advertisers used the line "there is no evidence that cigarettes are harmful" you would have had a high probability of succumbing to lung cancer.

Similarly, when new health products make positive claims of the health benefits, we should be extra cautious. This highlights a crucial point in risk analysis - we don't know what we don't know. The people selling this product act as if they have complete knowledge of the situation. They think they have done all the necessary trials to understand the side effects. Unfortunately, we know a lot less than we think. Seeing visible immediate impacts blinds us to invisible long term negative consequences. Baby formula, margarine, enriched grains, bloodletting, Vitaminwater, and opioids were thought to be revolutionary ideas until we found out (negative knowledge) that they had hidden health concerns.

Via negativa is an easier path toward betterment than other self-help ideas. You don't have to wake up at 4:30, take a cold shower, and run 6 miles. Via negativa is about observing what you do and cutting out the bad. You don't have to remember to do much, which I prefer. For example, with via negativa nutrition, we know a few simple rules, and we don't have to follow a diet that spells out calories, proportions, macros, or protein. The simplicity helps us to follow this diet for life rather than the few weeks after New Years.

A simple example of application of via negativa is the following. Imagine you are having trouble falling to sleep. While the doctor may prescribe you sleeping pills (addition), the real answer could be found through cutting out the bad (subtraction). For example, cut out screen time an hour before bed and cut out that 3pm cup of coffee.

Via negativa applies to personal finance as well. A crucial part of personal finance is spending within (or below) your means.

As the investor and entrepreneur Naval Ravikant says, "People who live far below their means enjoy a freedom that people busy upgrading their lifestyles can’t fathom."

This means cutting out an expensive car and an expensive house. It means cutting out excessive extravagant purchases. In the same vein, it means avoiding debt or other payments that do not compound wealth. Rather than relying on hitting it big, personal finance and building wealth is far more effective when we avoid bad decisions and big losses over the long term. Picking the perfect growth stock matters less than long term loss avoidance. The wealthy understand this.

"But Warren Buffett was not concerned about catching the top of the wave. He was far more interested in not wiping out. While most investors are motivated by a desire to make money, Buffett focused first on not losing money. In that way, Buffett behaved like Old Money. The majority of investors agonize over the prospect of getting out too early and missing out on the profits that would have made them rich. But the very rich don't fret so much about making money. They have money. Their greatest fear is losing it." - Maggie Mahar in "Bull!"

Via negativa is more important than ever. In the US, we are living in a world of abundance. There is more food, entertainment, activities, and options than have ever existed for a person. With abundance, filtration is more important than addition. Coupled with companies becoming increasingly clever about selling you more, we have to develop the skill of cutting out and avoidance.

Via negativa can be applied broadly to life. When looking for happiness or satisfaction, it is rarely going to come from adding an additional thing - a new car, a nicer house, or a new job. Rather, it will come from cutting out what makes you unhappy. Leo Tolstoy summarizes this in the Anna Karenina principle, “All happy families are alike; each unhappy family is unhappy in its own way.” All happy people are alike; each unhappy person is unhappy in their own way.