As with almost everything else in our era of acidic political discourse, Americans passionately diverge on the essential meaning of American history.

To many, American history is a story of triumph and exceptionalism, an extraordinary odyssey hatched by second-class British subjects whose posterity are now citizens of the most powerful civilization in the history of the world. To others, however, this is a profoundly narrow reading of America and its history, greatly in need of corrective and enlargement. While America’s achievements are plentiful, they are also troubling, coexisting as they do with atrocity, brutality and countless episodes of racial injustice.

Lincoln’s greatest lesson to us is that we should not wield conflicting versions of American history as weapons for conducting modern political discourse. Both histories are true and necessary to understand in order to forge consensus and foster progress. Conservatives should never hesitate to acknowledge our national sins. Liberals should rejoice at the extraordinary and unparalleled achievements of the United States. Lincoln did both and it imbued him with a holistic understanding of America that empowered him to be the greatest American to ever live.

Indeed, it was his unvarnished but idealistic understanding of our nation that enabled Lincoln to use what was right about America to remedy and ameliorate what was wrong with America.

Better than any president before him, Lincoln grasped the essential fluidity of the American ideal, understanding that each generation’s mandate is to strive not for a perfect union, but a “more perfect union,” anchoring our sense of perfection in the idealism of the Declaration, what he called “the apple of gold,” yet knowing each generation will inevitably fall short. The past, Lincoln understood, is more than an indictment — it is also a promissory note of what is possible when we possess a sober but hopeful belief in the power of each generation to re-create America in accordance with its own hopes and ideals.

As Lincoln observed in a speech in February 1861 as he made his way to Washington, D.C., “I am exceedingly anxious that the Union, the Constitution, and the liberties of the people shall be perpetuated in accordance with the original idea for which that struggle was made.”

Thus, Lincoln’s statecraft was simultaneous renewal and re-creation. Numerous examples demonstrate this powerful duality:

In his Peoria Address of 1854, Lincoln used his extensive and deep understanding of the Constitutional Convention to both acknowledge the sinister compromises made by the delegates, but also to ground his policy for the future in his argument that the clear hope of the men in Philadelphia was for the eventual extinction of slavery. As he says, “the plain, unmistakable spirit of that age, towards slavery, was hostility to the principle, and tolerance, only by necessity.”

In the Gettysburg Address, Lincoln acknowledges the generation that fathered our freedom and fashioned the political “proposition” that became the American creed, but argues that the Civil War had to be fought in order to complete “the unfinished work” and the “great task remaining before us.” This monumental “task” was to foster a “new birth of freedom.” This became the work of Reconstruction and eventually the Civil Rights Movement a hundred years later. Most Americans do not know that Martin Luther King Jr. lobbied President Kennedy for a “Second Emancipation Proclamation” a century after Lincoln issued the first one.

In his second Inaugural Address, Lincoln evokes the judgement of God, arguing that both sides bore culpability in the slaughter of 600,000 Americans—"He gives to both North and South this terrible war”—and yet, in the end of the speech, calls on the country to “bind up the nation’s wounds” and “finish the work we are in.”

Lincoln didn’t use the flaws of America to denigrate the nation. Nor did he exploit our triumphs to excuse what was unjust. Instead, he reverently understood that America’s greatest strength was its soaring ideals and transcendent principles. To abandon these was also to abandon the more practical dreams of practicing self-government, the promise of guaranteeing universal freedom, and the hope of instituting genuine due process for all.

We celebrate Lincoln today because at the heart of his life, his presidency and his approach to American history is the animating conviction that Justice is not a whimsical and subjective construct of political power. Lincoln believed in an objective moral and political order that cannot simply be altered because “the people” or the powerful want to choose otherwise; this is why he objected to “the people” of Kansas or Nebraska voting in favor of slavery. This is why is endlessly criticized Roger Taney’s Dred Scott decision. As Lincoln scholar Harry Jaffa explains, “Lincoln thought slavery was wrong and he did not think a vote of the people could make it right.”

In our turbulent times, we should follow Lincoln’s approach to both what is right with America and what must be our own work of making America the “more perfect union” we know it can and must be. Only then will we “lift artificial weights from all shoulders, to clear the paths of laudable pursuit for all ...”

Jeremy Adams is the 2012 Kern County Teacher of the Year, the 2014 California Teacher of the Year and the recipient of a Beautiful Bakersfield Award in Education. He can be reached at Jeremy_Adams@kernhigh.org.