In The Exorcist, the 1973 film that made Linda Blair a star and caused pea soup consumption to plummet, a man arrived at a house with a black bag and a Bible to drive out evil spirits.

But what does one bring to undo an exorcism? Comparable tools, actually.

Barack Obama swore on Abe Lincoln’s Bible.

This on the day Obama arrived at a White House that for eight years beheld science much like an allergist does black mold.

What we witnessed at the start of the George W. Bush presidency was an exorcism. Though consecrated by men of the cloth like the late Jerry Falwell, by and large it was orchestrated by and for big business.

For one, it would not acknowledge the truths and consequences of policies that bumped against the limits of the planet and its ecosystems. Examples:

* In 2006, nonscientists in the White House edited out congressional testimony from the Centers for Disease Control about the effects of global warming.

* In 2003, the White House sought to muzzle the top climate scientist at NASA.

* In 2001, it altered biological findings from the U.S. Fish & Wildlife Service about effects of oil development on caribou in the Arctic National Wildlife Refuge.

* It ignored findings about what a pedal-to-the-metal approach to snowmobiles would do to Yellowstone Park’s air.

One must admit, however, that the then-majority party’s problem with science wasn’t simply a devotion to greasing wheels for big business to roll across our land. Some of what it did was to make shameless and unconscionable offerings to the religious right.

Consider the concerted effort to link abortion to breast cancer, a connection disputed by the American Cancer Society and other cancer advocacy groups.

The Republican-dominated Texas Legislature wedged the specious claim into an “informed consent” law whereby women seeking abortions are to be force-fed it. Yes, by decree of Texas: misinformed without one’s consent.

Right now, the Texas State School Board is debating whether to, as Republican chairman Don McLeroy wants, require high school science classes to consider claims about gaps in the fossil record that would suit creationists’ assault on evolution theory.

McLeroy is a dentist. He’s also a creationist. It’s a peculiar algorithm by which we turn to a dentist rather than to biologists when deciding how to teach biology.

That’s the equation Obama wants to change. Under the new calculation, we would be guided by science, rather than guiding science where our religious beliefs want it to go — like the young-Earth belief shared by creationists.

Emblematic of where the other approach took us was a $2.3 million federal grant, when the Bush administration was young, to study the power of prayer.

It started out in assessing whether prayer could help resolve a woman’s fertility issues. You’ll be surprised to know it proved inconclusive.

Meanwhile, when actual experts had actual scientific proof about reproductive matters, the administration ignored them.

The Food and Drug Administration gave an exhaustive review to over-the-counter use of Plan B, the “morning-after” birth-control pill, and gave it an unqualified endorsement. The Bush administration stalled with all its might before finally giving in. We are left to wonder how many unintended pregnancies, and abortions, could have been prevented in the interim.

Almost no empirical evidence shows that abstinence-only programs in schools avert pregnancies and sexually transmitted disease in comparison to comprehensive sex education. But don’t expect evidence to stand in the way of dogma, which is always more aromatic.

The irony is that Bush popularized the phrase “sound science.” Based on his practice, what he meant was science that sounded as if it could fit within one’s political, religious and economic belief systems.

An oxymoron, in other words.

John Young’s column appears Thursday and Sunday. E-mail: jyoung@wacotrib.com.