Since then of course the Church has recognized and appreciated the dimmed light of truth that can be credited to the faculty of human reason unassisted by grace and revelation. When these truths are brought into the light of Christ we see a majestic and symphonic harmony manifesting the compatibility of faith and reason: early in the work of Tertullian's contemporary Clement of Alexandria; later in the thought of both Origen and Augustine who synthesized Plato with the Christian revelation; and culminating in Thomas Aquinas' masterly reconciliation of faith and reason through a careful reading of the Gospels, the Church Fathers (especially Augustine and Dionysius), Aristotle and Plato.
So for some 1500 years or more, there has been a solid answer to the question of "what has Athens to do with Jerusalem?": namely, that faith and reason are mutually compatible and supportive, "like two wings on which the human spirit rises to the contemplation of truth" as John Paul II wrote, and noting that "each without the other is impoverished and enfeebled."
America was largely founded on a harmony between Jerusalem and Athens: that while not necessarily a Christian nation, and as much a project of Enlightenment values as Judeo-Christian values, we were certainly to be some sort of "city set on a hill" that recognized that we ought to be ordered somehow to the "Laws of Nature and of Nature's God", and built on the premises that "all men are created equal, that they are endowed by their Creator with certain inalienable rights, that among these are life, liberty and the pursuit of happiness." Our model for self governance was framed within a clear expression of the what was classically called the "common good":
We the people of the United States, in order to form a more perfect union, establish justice, insure domestic tranquility, provide for the common defense, promote the general welfare, and secure the blessings of liberty to ourselves and our posterity, do ordain and establish this Constitution for the United States of America.Given the recent turn in the American political landscape, where faith is now under direct attack by the Executive Branch, and reason has been replaced with the crass utilitarianism of neo-conservatives (a term that has nothing to do with conservatism, or more properly "classical liberalism", but is all about unbridled and ethically unmoored market forces, globalism and expansionist policies meddling in foreign lands for oil interests, bureaucratic centralized Statism, and the reduction of the human person to an economic unit for production, consumption, and taxation) along with the libertinism and moral nihilism of the hard Left, the question can well be reframed:
If "Jerusalem" is given as the term of faith where we are called to order our civic order according to the plans and purposes of God; and "Athens" to mean the highest aspirations of the human community on the natural level, where the whole of the society is ordered to a common good of civil tranquility, justice, peace, the rule of law, and to create a political structure that allows for true human flourishing and integral human development (bear with me, I realize that was all highly idealistic in the Hellenistic age and only limited to the male landowners, but the principle is still extendable to the universal human condition); then today we might well ask:
"What has Washington DC to do with either Athens or Jerusalem?"
As far as I can tell, "nothing".