Hart's point is that the sharp divide between reason (ratio) and faith (fidei) is a modern experiment gone wrong. He calls the division a "tarnished relic of the seventeenth century." And its result remakes human reason as a faculty divorced from all assumption "dispassionate and disinterested." But this is wrong.
"All reasoning," says Hart, "begins from a venture of trust whose truthfulness can be ascertained only at the end of the sequence of postulates and predicates and judgment to which it gives rise." As I read this, I think of David Hume taking arrogant reason to task for too closely wedding cause and effect. Hart goes on to say why he can make this assertion.
Every assertion he says assumes a metaphysic in which the mind and the world connect and are true to one another. Enlightenment reason cannot boast this connection.
The materialist by force of will ignores his own assumptions, choosing to focus instead on the practical utility of every question. Who cares why it works. It works. And that it works becomes the all in all. The context from which the question arises eventually ceases to be noticed. Consider this comment from physical chemist Dr. Peter Coveney: "In modern biology and medicine today you would find most people not even trying to think in theoretical terms. . . What we call "Baconian theory' says, don't worry about a theoretical underpinning, just make observations, collect data, and interrogate the data." Hart calls this a true fideism. "The unyielding rationalist turns out to be the most irrational fideist of all: one who believes in reason even though there cannot possibly be any reason for that belief." With Bacon, Descartes project is similarly framed. The self is trusted to posit reality from its own foundations, an attempt at faith from below. It was only a short path to rational idealism, to Hegel, and the nihilism of postmodernity. "Without that original trust, that spiritual commitment, reason is not reason at all, but the purest irrationality."
The worldview that preceded the Enlightenment, the Medieval mind, was more integrated. It could wed mind and world and so posit truth because, behind mind and world it understood the unity and oneness by the one God.
Hart's critique of ascendant reason looks not only to the assumed metaphysic, but also appeals to natural selection. This is a move I've written about before, in that case employed by Alvin Plantinga. I think it is a devastating critique. It is simply this: if the human mind evolves, then how can we trust it to guarantee knowledge? Put another way: how can we trust reason if it is but another evolved faculty?
This is where I think theistic evolution is another fancy way of saying God made the world. The Medieval mind understood that God's unity was necessary to secure truth as the product of particulars embedded in a cosmos. The theist post-Darwin has to evoke God's triune plurality as well to ground mission, action, change--eschatology.
So then, I've had all of these pieces scattered around, but the confidence to finally--once and for all--to put them together was lacking. No longer. I'm willing to say that reason and faith are one because God's logos made the world in wisdom. I'm willing to suffer the charge of fideism and supernaturalism and the suspicion of anti-intellectualism or just plain naivete.