In human history, no practice has more profoundly advanced human understanding of the natural world than that of science. So it seems tragic, in the year 2014, that science should require a defense (by a comedy writer, no less). And yet, in both the national dialogue on issues such as climate change, evolution, and vaccines, and in recent conversations I have had with people I consider reasonable and well-educated, I have discovered a shocking anti-science narrative emerging; a fundamental ignorance of or distrust of science that expresses itself in opinions such as:
*Scientists have been wrong in the past and thus should not be trusted now
*Scientists are biased by personal prejudices, financial incentives, and the desire for personal or professional success, and therefore their conclusions are suspect
*Scientific results are not certain, and therefore they can be discounted
*Science is just another way of knowing that should not be given primacy over other ways, such as intuitive knowledge or personal experience.
*Some scientists disagree with the consensus view so there is no way to assess who is right.
*Science is the cause of the problems resulting from technology and therefore suspect.
*Policymakers may ignore science on the grounds that they, themselves, are not scientists.
While some of these opinions are simply misguided, others, at some level, could offer potentially useful critiques of the actual practice of science. However, none of them represent any kind of a rebuttal to the basic, essential fact that, for all its imperfection, hubris, sloppiness, or uncertainty, science works. Like a flashlight shined into dark spaces, science shines the light of its analytical method into the opaque mysteries of the natural world and makes them comprehensible. And it does this over and over again, in field after field of scientific inquiry.
Science is able to achieve its results by following a rigorous method of investigation involving the creation and testing of hypotheses against observational evidence. At every stage, these hypotheses are subjected to intense challenge. First, they are tested through the process of scientific research. Then through the process of publication and peer review they are subjected to challenge by the larger scientific community. After publication, they continue to be challenged, corroborated, modified, or refined by new research and new hypotheses. Science that has withstood this onslaught of skepticism is seen to be accurate and trustworthy, and consequently it earns the backing of a consensus of practicing scientists.
Because science is based on such a strong foundation of evidence and analytical rigor, anyone who would challenge science, particularly well-established science such as that on evolution, climate, or vaccines (or, for that matter, gravitation and quantum mechanics), rightly faces a very high burden of proof, a burden which most science skeptics fail even to acknowledge, much less satisfy. Science cannot be refuted by appeals to intuition or personal experience, attacks on the character or motivations of scientists, accusations of institutional bias, or by "cherry-picking" a particular authority figure, alternative theory, or research study. It cannot be denied because it is inconvenient, or because one dislikes the policy implications. It cannot be dismissed on supernatural grounds or through suggestions of conspiracy. It cannot be undermined by dreaming up alternative hypotheses (unsupported by strong evidence), or by pointing to remaining uncertainties in the established theory. All these are utterly inconsequential as refutations -- not because scientists "know better" than the rest of us -- but simply because they fail to convincingly meet the burden of proof.
Science works, and so we accept its findings -- not because we have "faith" in them or because they are perfect -- but because in an uncertain world, we wish to use the best available information to solve our problems, improve our condition, and understand our situation. This means, in the year 2014, accepting the current scientific consensus that vaccines are well-understood, safe, and effective. It means accepting the current scientific consensus that humans are causing the climate to change through the emission of atmospheric carbon and other greenhouse gasses with results that will almost certainly range from bad to catastrophic. It means accepting the current scientific consensus that evolution through natural selection is the theory most likely to describe observed biological diversity at all levels from DNA to species, including human beings. Certainly, we should maintain a "healthy skepticism," but we should focus that skepticism, not on the science, but rather on the claims of those who profess to be in possession of some special knowledge or authority outside of the formal scientific process. To do otherwise would be to deprive ourselves of the greatest tool for human advancement mankind has ever known, at exactly the time when such a tool is needed most.