Almost nothing unites the commentariat these days.  But if there is a consensus about anything, it is in the almost universal condemnation of our toxic political culture.  We are certainly more polarized than at any time in living memory.

There are broad historical reasons for this, mostly having to do with the ideological realignment of our two predominant political parties into philosophically unified parties of left and right.  But the larger story is in the fundamental incompatibility of the competing ideologies.  A clash of philosophies challenges the foundational moral principles of the respective combatants and represents an attack on the very underpinnings of their most sacred values.  It is no less than an assault on basic notions of right and wrong; something in defense of which man will expend his last full measure of living effort.  That is why politics has lately become so vicious.  The adversaries are defending that which they hold most dear: the integrity of their moral systems and their notions of truth.  It is a war fought at the most visceral level, for defeat means destruction.

The first sixty years of the twentieth century saw an international liberal zeitgeist that admitted of little effective opposition, even in the United States.  Indeed, there was, in our nation, no organized political counter-movement until the late '40s, the consequence of which were an unchallenged predominance of liberal opinion that became so pervasive as to achieve intellectual and social fashion.  It became the operating assumption of modern thought.

Until the '60s, both parties were predominantly center-left as they were forced to accommodate their respective right and left wings but bowed to liberalism's dominating orthodoxy.  At the end of the '60s, the Democratic Party became a true party of the left with a unified ideological message and an enforced philosophical conformity.  The Republican Party was not far behind, as the fall of the party establishment, represented by the immolation of Richard Nixon, provided an opportunity for a newly resurgent conservatism to reassert, with renewed moral authority, the momentum lost with the defeat of Goldwater in 1964.

By 1984, the parties had largely realigned along ideological lines even though Republican establishmentarians continue to exercise a moderating influence unknown in the Democratic Party -- itself devoid of leavening influence.  This set up the polarization to come.  For a time, the parties were led by earlier generations that recalled the days when compromise was still possible because the parties were not ideologically fixed.  That generation is now gone, and the national schism in full flower.

Most voters are not ideologically driven.  Indeed, most have no conscious understanding of the philosophical premises that undergird the two competing public ideologies.  They believe that government has purposes, and they elect officials to solve problems that must be solved collectively.  They expect, therefore, officials of all ideological stripes to work together in a spirit of cooperation to "do the people's business" and solve the great problems of the day.  They do not understand that solutions require public policy prescription, and public policy is inextricably linked to the philosophical underpinnings that define those who shape it.  They do not realize that, at root, the divergent ideologies that animate the political poles are fundamentally incompatible in their premises and their goals.

Ideology is defined by philosophy and 21^st-century American ideology is merely the culmination of three millennia of philosophical ferment -- its schism, the result of a divergence of theory starting with Aristotle and Plato.

Why does this matter?  It matters because in our current political climate, we most often find ourselves talking past one another.  We cannot believe that any rational person could hold views so at odds with our own.  Each side is left to conclude that the other takes its positions in bad faith, out of partisanship, or for simple political advantage.  We see it in the pages of the New York Times, whose editorial writers cannot fathom the idea that conservative insistence on spending cuts could be the result of principle rather than a venal desire for electoral gain.  That failure of imagination poisons the well of discourse, making compromise nearly impossible as each side wraps itself in self-righteous disdain for the other and views compromise as unprincipled.  The result is political paralysis.

The fact is that right and left each simply do not understand how the other thinks because the philosophical premises upon which each proceeds are diametrically opposed to the other's.

To understand the roots of the conflicting philosophies, then, is to understand their fundamental incompatibility -- the result of antagonistic worldviews and irreconcilable premises -- and that compromise will be found, if at all, only on matters involving no foundational principle or at times of such extremity that principle must yield to necessity.  Otherwise, it will occur either when the unideological middle organizes around unprincipled pragmatism, presenting the danger of the rise of populist demagogues, or when one side convincingly defeats the other.

Plato is the father of American leftism.  He was a rationalist -- a philosopher who believed that truth was discovered through the application of logic unconstrained by experience.  His was unleavened idealism, and his description of an ideal political system is one derived from what he imagined would result in the best, most ordered society from which all would benefit.  He proceeds from two basic premises.  The first is that transcendent truth is knowable a priori and derived by the mind of man applying logic to an analysis of abstract principles.  The second is that it is the function of government to shape society and, to that end, to organize its citizens and institutions with the objective of creating the defined ideal.

Not surprisingly, Plato's system has never, in the history of mankind, existed.  It is not, mind you, for lack of trying.  The highways of history are littered with the corpses of failed utopian experiments.  It is just that the limits of logic uninformed by experience are too profound to allow for the forced creation of an ideal society when it is made up of individuals.  Man is too mutable, the options too varied.  But Plato's progeny have, through the millennia, adopted his premises in a direct line of thought from Plato to Augustine to Descartes to Leibnitz to Kant to Hegel to Marx to modern liberalism.  Each accepted as its premises, first, that the truth was knowable and should be derived by logic without reference to experience and, second, that government exists -- and should exist -- to shape society to the ideal and, with it, to bend the will of the individual to the service of the defined greater good.

Aristotle, on the other hand, held that truth is far too complex to know through the bare application of logic to imagination because the variables are too numerous to enable the thinker to find that truth without reference to known variations of existent, provable fact.  He began with an analysis of all known governmental systems and developed an idea for the best possible government, based on what had been proven possible.  Aristotle took into account the changeability of human nature.  Indeed, unlike Plato, he took human nature itself into account.  In developing his theory, he assumed two premises: first, that truth can be determined through logic, but only if it is based on empirical observation, and second, that government exists to protect its citizens so they can freely create their own society born of liberty and choice.  His thought, too, has heirs in a line from Aristotle to Aquinas to Hobbes to Locke to Burke to the American Founders and to modern conservatism.

The predominant ideologies of modern America are the result of these two intellectual strains.  Liberalism defines its ideal society without reference to what has gone before -- by the application of logic to abstraction ungrounded in historical experience.  That ideal is the equality of all -- something demonstrably unachievable, given variations in man.  Liberalism holds that society can and should be shaped by an activist government.  Its concept is that the individual can flourish when the ideal society is established -- i.e., one that will free him from the constraints imposed by a primitive state of free competition.  Its goal is an articulated ideal in which individual struggle is minimized and social stratification collapsed into equality of result.  That no such society has ever existed appears to be a matter of indifference.

Robert Kennedy articulated this worldview in his version of Shaw's formulation: "Some men see things as they are and say 'why?'  I dream things that never were and say 'why not?'"

Conservatism demands that public policy be based on empirical experience.  The underlying assumption is the primacy of perception as a means of determining truth.  The Founding formulation was that governments are instituted among men to protect the freedom and safety of the citizen and not to shape his society.  Hobbes and Locke invented English empiricism, and their political philosophies are based on an analysis of the natural inclinations of man, not on an abstract ideal.  It is on that basis that their political systems were constructed.

It is impossible to square the concept of government as an authoritarian project through which freedom is found only after the ideal society is achieved with the concept of government as protector, freeing its citizens as a foundational concept so they create their own society through the exercise of freedom.  In public policy, it translates into an intractable tension between those who see government as constraining and those who see it as protective.  The problem can be seen in current public policy debates.

What is the result?  In an ideal society, man's law can achieve all by the mere willing of truth.  So liberal legislators pass laws that require the achievement of unachievable ends: automobiles that can obtain mileage goals not possible under current technology; energy generation through efficient solar photovoltaics that simply do not now exist and will not exist for decades, if ever; confiscatory taxation designed to take from those who accomplish to give to those who don't in order to achieve equality of result.  As if merely passing a law could make it so.

The burgeoning American welfare state represented by Lyndon Johnson's Great Society and ObamaCare are enacted despite overwhelming empirical evidence that not only do such programs fail to achieve the goals they seek, but they also generally make matters worse for the intended beneficiaries.  And, in the bargain, they bankrupt the governments that sponsor them.

The divide in fundamental ideological premises was on full display during the recent debate over national health care legislation, and the basic incompatibility of the competing philosophies formed the basis of the drastic polarization of our politics on that issue.  On the one side were the Platonists, who defined the ideal society as one in which all had equal access to health care.  On the other were those Aristotelians who pointed out the inconvenient fact that not only had such efforts failed in the European nations in which they were implemented, but, in addition, the programs threatened to bankrupt the governments sponsoring them and had sapped the ambition of the citizens who depended on them.

The liberal project was to use the tools of government to create its ideal society, a large component of which was complete equality among all citizens.  It did not matter to program sponsors that the experiment had never worked.  It should work.  Their logical formulation based on an abstract ideal told them so.  Raining on their parade were those who pointed out that if an experiment repeatedly fails, the premises are wrong.  It was a classical clash of paradigms, and there is no way to reconcile them.

Attacks on the proposal became attacks on the moral sensibilities of its proponents.  The proposal itself represented an attack on the moral principles of its opponents, who believe that public policy should be based on fact, and fact is established by empirical observation.  Attacking the proposal became an assault on the effort to achieve the ideal society, and, thus, on the moral imperative of creating it.  It became an attack on morality itself.

On the other side, proposing to extract by governmental force the resources from individual initiative necessary to implement a program that plainly would not work went against the need to base action on the empirically provable and abrogated the moral injunction against taking from one to serve the other.  Using government to engineer the perfect society and to bend the individual to the good of the whole was seen as deeply and fundamentally immoral.  Modern Aristotelians viewed, with horror, the left's authoritarian project, and so went the debate.

Thus, in modern American politics, each initiative becomes a moral crusade, and modern American politics becomes increasingly toxic.  Until historical events convincingly demonstrate that one side or the other is right, the debate -- and the attendant venom -- will continue.  But that answer may come sooner than we might have expected.  The liberal experiment in Europe has lasted seventy years, and it is collapsing under the strain of history -- of experience, as the Aristotelians have predicted.  When the house of cards finally falls, perhaps, then, even American liberals will acknowledge that truth is a function of observation, not of imagination -- that the ideal unleavened by experience is folly.

We can, if we will, avoid Europe's fate if we simply acknowledge that experience means something and accept its lessons.  The experiment in Europe has failed.  We need not try it again.  We will again enjoy the success that made our nation the last, best hope of mankind if we recall that that success was built on an empirical foundation and based on the premise that there is no limit to what can be achieved by the individual left free by his government to create as he will.