Human cognition is linear. You push something harder, it moves further. You spent more money, the larger the debt. Someone punches you harder, it hurts more. We intuit that a system changes in the same proportion we change its properties.
These are mostly banal examples, but this cognition translates to larger topics as well. How many immigrants shall be let in, how many social programs shall be slashed, what is the ultimate doom of humankind. Specialists on these topics base their evaluations on an extrapolation of past data, a line roughly drawn through the points. The expectation that what comes next is extrapolated from what came before. The basest of all mathematical tools for the policy makers is the linear regression.
Scientists have known for long that the world is nonlinear. Proportional increase in temperature does not necessarily lead to proportional change in the properties of water – think of liquid water turning into ice. It may be sunny one day and in a couple of days it could rain. The mathematician knows that that a chaotic system has stable attractors, one could find itself in one attractor, one conceptual framework, universe, and just in an instant, the world shatters to bring out the next. But the tyranny of linear cognition affects them as well. Solvable scientific systems tend to be linear – the oscillation of a pendulum, the small perturbation of the sound wave, an electron stuck in a potential well – much of the techniques developed to solve non-linear equations are built by appealing to these systems, to this basic linear cognition. That the value of a function changes in proportion to some input variable is perhaps the most basic of all quantitative intuitions.
Human linear cognition doesn’t necessarily reflect the measurable reality. If that was the case, one could apply a linear regression to the next timestep of the universe, and predict with certainty the revolutions, stock markets, the weather, the exact point in the universe a star will be born. Forecasting is hard. But the big questions about life, from the personal, the political, and ultimately, how we organize as humans and how we relate to the earth, are tackled through our linear cognition while we know from empirical evidence that universe is very rarely linear. More carbon emission leads to just a slightly different reality than the one we live in. The hike of rent and property values may lead to a couple of homeless people more. But what if homelessness and carbon emission and global warming are nonlinearly coupled?
The Earth is a complex system governed by nonlinear interactions between humans, plants, animals, the ocean, the atmosphere, the influx of solar radiation. An example of a nonlinear relationship within the system is the connection between the glaciers and climate change. Increasing temperature reduces the volume of glacial ice, which in turn leads to less solar rays being reflected back into outer space, this in turn, heats up the earth, shrinking the ice further, creating a feedback effect. This effects interact with human society: melting of the ice in turn raises the sea level, destroying ecosystems, annihilating whole economic sectors, making the poor poorer, causing mass migration and refugee crises. Once this critical point is reached, what we know from past scenarios will not help in evaluating the present – because the world that was left behind will be radically different and therefore the models developed to represent that world will not help in the present. It will become the no man’s land for the technocrat and their linear regressions and machine learning algorithms.
Liberalism is the consequence of linear cognition because it assumes the world of tomorrow will look similar to the one of today – a little bit more pollution, more capitalism, a couple of years more of life expectancy, a crude line you draw through the scatter of points. Everything will be alright provided we move slowly, according to what we have learned from the scatter plot. Anything that steers too far is unrealistic, the domain of the political fringe, and more importantly, lacks evidence. Liberals cannot imagine either the apocalypse or utopia because both of them depict radically different scenarios that do not quite fit in their linear world.