Yet we might ask, why be realistic? After all, in philosophy, reflections upon unrealistic hypotheticals can be fun and, furthermore, provide interesting and important insights. Philosophers are famous for talking and arguing about zombies, brains in vats, and bizarre trolley problems that are incredibly unlikely to occur in reality. Such strange mental exercises are designed to test us, to test our ideas and explanations, challenging us to be consistent and to make decisions about the bullets we are willing to bite. The unrealisticness we find in ideal theory, however, is different—it’s a convenient escape hatch that allows us to evade consistency, to avoid having to bite any bullets. If imaginary constructs like philosophical zombies help us isolate and focus on the difficult questions, then ideal theory simply assumes those questions away, content to concern itself with how people should act or might act given the right set of hypothetical conditions. Ideal theory as we find it in thinkers like Rawls works backwards from a set of preferred policies; it carefully explains that if we grant certain assumptions about human behavior and indeed the human mind (which assumptions, we should add, are quite controversial), a certain set of policies and political structures best accomplish justice. For ideal theorists, the state is an almost perfect embodiment of justice, staffed by high‐​minded altruists, by seemingly faultless model citizens or philosopher‐​kings (on which more below). In contrast, people acting in civil society and in the market are self‐​serving, uncaring and uncharitable, focused on maximizing their personal gains rather than the common good. That such pronounced behavioral asymmetry is so quietly taken for granted–almost completely unnoticed and unremarked–is perhaps the single most important fact in the history of political thought.

Libertarians tend to think that this is the wrong way to go about building a theory of politics and justice—that we should factor in how people actually behave (and have behaved in the past). When we give such considerations their due, government begins to appear significantly less benevolent. The real, historical state is conspicuously absent from the work of political theorists like Rawls (and in the Rawlsian tradition generally), incongruent with their ungrounded picture of the state as the servant of justice. Simply, the real historical state is designed not for protection, but for invasion; it is designed not to safeguard justice and the rule of law, but to carry out injustice and protect the unaccountability of those who hold power. Still, even if we assume the good intentions of those who hold political power and make laws today (and we should), government is not capable, as an empirical matter, of serving the ends ideal theorists would have it serve. Because laws are executed and enforced by actual human beings, who have their own incentives, biases, prejudices, and values, they’re never applied ideally or equally. The law is not a spiritual being with its own existence and motivations, animated by platonic ideals of justice; it operates unevenly, through flawed and self‐​interested people.

Criminal law and procedure provide notable examples of rules applied unequally and discriminatorily. If you are poor or a person of color, you will fare differently — worse — in the American criminal justice system than someone with more money or a white person. For example, “African Americans are incarcerated at more than 5 times the rate of whites.” American government at the local, state, and federal level systematically disregards the rights of certain unfortunate groups; the abuses visited upon these groups, by police and prosecutors, for example, are by now a well‐​documented national crisis of justice, an obvious extension of America’s history of slavery, segregation, and racism generally.

Further, and apart from any ethical shortcomings or incentive problems, policymakers are not omniscient; they can’t see into the future and often fail to account for the possibility that their favored policies won’t play out as they expect. Price control measures (in the form of either legally‐​enforced price floors or ceilings) provide an example of unintended consequences. Progressives, socialists, and others who would use coercive state intervention to plan or otherwise manipulate the economy have a confused, indeed upside‐​down, understanding of prices; they incorrectly see prices as levers that can be tweaked to determine value, rather than as metrics responding to value, showing what people already value. Thus, when politicians ban prices above or below a certain threshold amount, they do not thereby alter reality, actually succeeding in their attempt to change the value of a particular economic good or service. They couldn’t possibly do this, for economic value is something that exists as a result of the subjective opinions of thousands (or millions, or billions) of separate individuals. Prices act as a shorthand means of communicating the sum of these opinions, telling us how best to allocate our energies, time, and resources. If government officials do not allow us to price goods and services how we otherwise would—i.e., in the absence of coercion—the opinions do not simply disappear; they will find other outlets, other ways to express themselves. We find new ways to ration our energies, time, and resources. As economist Antony Davies explains, “Minimum wage creates unemployment amongst those who are less skilled, precisely the people we’re looking to help [by enacting minimum wage laws].” Today, we can see unemployment as an unintended consequence of minimum wage laws, because we know that the supporters of such laws don’t want to cause unemployment. Interestingly, though, the progressives of days gone by wanted to do exactly that, to exclude certain undesirable groups from the American workforce.

Human society is an enormously complex web of relationships and institutions of all kinds — social, governmental, economic, charitable, religious, etc. The density of these variables makes accurate prediction of a given policy’s long‐​term effects exceptionally difficult. Consider the stock market, a comparatively tiny piece of human activity on which we have an enormous amount of data, gathered every second and giving us a detailed picture of the functioning of the mechanism. Even in this case, experts who dedicate their lives to making accurate predictions regularly make mistakes, unable to anticipate the movements of markets. In his essay “From Freedom to Bondage,” Herbert Spencer explains: