# How to tame a complex system

I get a lot of pushback to the idea that [humanity can “master” nature](https://newsletter.rootsofprogress.org/p/the-surrender-of-the-gods-part-2). Nature is a complex system, I am told, and therefore unpredictable, uncontrollable, unruly.

I think this is true but irrelevant.

Consider the weather, a prime example of a complex system. [We can predict the weather to some extent](https://ourworldindata.org/weather-forecasts), but not far out, and even this ability is historically recent. We still can’t control the weather to any significant degree. And yet we are far less at the mercy of the weather today than we were through most of history.

We achieved this not by controlling the weather, but by insulating ourselves from it—figuratively and literally. In agriculture, we irrigate our crops so that we don’t depend on rainfall, and we breed crops to be robust against a range of temperatures. Our buildings and vehicles are climate-controlled. Our roads, bridges, and ports are built to withstand a wide range of weather conditions and events.

Or consider an extreme weather event such as a hurricane. Our cities and infrastructure are not fully robust against them, and we can’t even really predict them, but we can *monitor* them to get early warning, which gives us a few days to evacuate a city before landfall, protecting lives.

Or consider infectious disease. This is not only a complex system, it is an evolutionary one. There is much about the spread of germs that we can neither predict nor control. But despite this, we have reduced mortality from infectious disease by orders of magnitude, through sanitation, vaccines, and antibiotics. How? It turns out that this complex system has *some* simple features—and because [we are problem-solving animals endowed with symbolic intelligence](https://newsletter.rootsofprogress.org/p/the-problem-solving-animal-part-3), we are able to find and exploit them.

Almost all pathogens are transmitted through a small number of pathways: the food we eat, the water we drink, the air we breathe, insects or other animals that bite us, sexual contact, or directly into the body through cuts or other wounds. And almost all of them are killed by sufficient heat or sufficiently harsh chemicals such as acid or bleach. Also, almost none of them can get through certain kinds of barriers, such as latex. Combining these simple facts allows us to create [systems of sanitation](https://blog.rootsofprogress.org/draining-the-swamp) to keep our food and water clean, to eliminate dangerous insects, to disinfect surfaces and implements, to equip doctors and nurses with masks and gloves.

For the infections that remain, it turns out that a large number of bacterial species share certain basic mechanisms of metabolism and reproduction, which can be disrupted by a small number of antibiotics. And a small number of pathogens once caused a large portion of deaths—such as [smallpox](https://blog.rootsofprogress.org/smallpox-and-vaccines), diphtheria, polio, and measles—and for these, we can develop [vaccines](https://blog.rootsofprogress.org/immunization-from-inoculation-to-rna-vaccines).

We haven’t completely defeated infectious disease, and perhaps we never will. New pandemics still arise. Bacteria evolve [antibiotic resistance](https://ourworldindata.org/antibiotics#antibiotic-resistance-threatens-our-ability-to-treat-common-infections). We can sanitize our food and water, but not our air (although [that may be coming](https://blueprintbiosecurity.org/works/blueprint-for-far-uvc/)). But we are far safer from disease than ever before in history, a trend that has been continuing for ~150 years. Even if we never totally solve this problem, we will continually make progress against it.

So I think the idea that we can’t control complex systems is just wrong, at least in the ways that matter to human existence. Indeed, a key lesson of systems engineering is that a system doesn’t need to be perfectly predictable in order to be controllable, it just has to have known variability.[^eewkqx2idgp] We can’t predict the next flood, but we can learn how high a 100-year flood is, and build our levees higher. We can’t predict the composition of iron ore or crude oil that we will find in the ground, but we can devise [smelting](https://blog.rootsofprogress.org/iron-from-mythical-to-mundane) and refining processes to produce a consistent output. We can’t predict which germs will land on a surgeon’s scalpel, but we know none of them will survive an [autoclave](https://en.wikipedia.org/wiki/Autoclave).

So we *can* tame complex systems, and achieve continually increasing (if never absolute or total) mastery over nature. Our success at this is part of the historical record, since most of progress would be impossible without it. The “complex system” objection to the goal of mastery over nature simply doesn’t grapple with these facts.

[^eewkqx2idgp]: Eric Drexler makes this point at length in Radical Abundance.