It took a while to discern the guiding ideology behind the Bush administration's poisonous science policies. The real problem wasn't tax cuts and war spending, even though the combination did strangle domestic programs so severely that scientists at the nation's premier physics lab were ordered to take unpaid leave, and the government is allocating 13 percent less to biomedical research in 2009 than it did in 2004. Nor was the culprit the sop that Bush offered the religious right in 2001 by banning the use of federal money for research on new lines of human embryonic stem cells, paralyzing the field for eight years and sending some of the nation's most promising young biologists overseas. It wasn't even Bush's refusal to take any action to reduce greenhouse gases, allowing U.S. emissions to grow by 178 million tons during his years in the White House and making the needed cuts that much deeper now. No, Obama and Congress can reverse all of that if they want to. The truly poisonous legacy of the past eight years is one that spread to much of society and will therefore be much harder to undo: the utter contempt with which those in power viewed inconvenient facts, empiricism and science in general.

Look at how Bush justified inaction on greenhouse gases. Not by arguing that cuts would have cost too much, a stance that would at least have been intellectually honest, albeit debatable. Instead he had political appointees eviscerate scientific reports on climate change, censor climatologists and exaggerate scientific uncertainties, with the result that tens of millions of Americans think that the existence and cause of global warming are matters of opinion. The same mind-set governed abstinence-only sex education. The administration could have argued that any curriculum other than one teaching "no sex before marriage" was immoral. Again, intellectually honest. But no: instead it manipulated "scientific" evaluations of the programs to make them seem more effective at preventing teen pregnancy. The justification for limiting embryonic-stem-cell research was even more insidious. The White House and its allies could have taken the morally sustainable position that 32-cell embryos are human beings and thus cannot be destroyed. Instead, they claimed, falsely, that adult and umbilical-cord stem cells can treat 72 diseases and conditions, no embryonic cells required.

It turned out that the Bush administration had about as much respect for scientific facts as it did for facts about weapons of mass destruction in Iraq. As one official explained to author and journalist Ron Suskind in 2002, the administration had nothing but disdain for what it called "the reality-based community," people who "believe that solutions emerge from your judicious study of discernible reality." That would be science. Instead, said the official, "we create our own reality." That translated to such things as filling federal health-advisory boards with doctors who claim, against all scientific evidence, that low levels of lead are not neurotoxic to children. The message that expertise and facts do not matter has had a poisonous effect on young people's desire to go into science, which has played no small part in America's losing its competitive edge in R&D.

It has also undermined public trust in the integrity of science. That gives Obama a steep hill to climb as he tries to seize opportunities that Bush wasted, whether it's to convince Americans that climate change is real and man-made, that embryonic stem cells offer avenues to cures that adult stem cells do not, or any of the other science-based issues he'll grapple with. But Obama has shown, through his policy positions and choice of advisers, a respect for the values of scientific inquiry, for experts and expertise, for reaching conclusions based on evidence and disinterested empiricism rather than wishful thinking. The late senator Daniel Patrick Moynihan of New York said that everyone is entitled to his own opinion, but not to his own facts. We will soon have an administration that agrees, freeing science to make the contributions to the nation's health, energy security and prosperity that only it can.

© 2008