Because historians do not understand science, scientists write their own history. So when scientific opinion changes—when a science turns out to have been a pseudoscience—the dead or powerlessly retired scientists who pursued it are sorted ex post facto. The ones who anticipated the change stay scientists; the ones who fell for it turn out to have been pseudoscientists. Truly they were pseudoscientists all along—everyone knew it—but that media, that damned media, they were the ones who made it seem otherwise—we scientists always knew better; it's your fault for being gullible, you cargo cultists.
You can watch this happen to string theory. In one direction or the other expect to see it in climatology. Let us rehearse the explanations in advance. Someday you may recognize one or the other as a news item or a footnote in history.
Despite the overwhelming evidence for the anthropogenic origin of global warming, a movement of so-called skeptics, organized ultimately through the resources of corporations and political parties whose interests were threatened by the urgent measures the situation required, were able able to delay action until the forces behind climate change had become irreversible. Certain scientists, some through misplaced but sincere convictions, but most because it was convenient and attention-getting, continued to cast doubt on the evidence even after the scientific consensus was certain. Nonetheless, none of the best scientists failed to see reason, and it is simply false to assert, as some have, that scientists themselves were at fault.
In the tense political atmosphere of the early 21st century it was only natural that political movements were eager to enlist scientific evidence to support their policies. Given the apocalyptic mood of the time—a quick look at the box-office returns for the first decade of the century will show that the impending end of the world was a cultural commonplace—it is unsurprising that what developed was a superficially scientific vision of the apocalypse. The media too were part of this zeitgeist, and exaggerated a concern many scientists had with the unknown effects of carbon dioxide, and certain alarming high-level trends, into a political movement complete with speeches, rallies, and platforms. Nonetheless, none of the best scientists failed to see reason and it is simply false to assert, as some have, that scientists themselves were at fault.
I am not proposing a debate. I am not trying to convince you of anything except the irrelevance of your convictions. Climate change is just a convenient subject.
(For the record my view is better safe than sorry. The absence of anthropogenic global warming would be harder to explain than its presence; I therefore am in favor of anything short of irreversible geo-engineering.
Though I do admit to disgust for those who condemn "economists' reliance on models" with one fork of their tongues, while the other extols "the proven science of climate change"—as if modeling the homeostasis of the economy were any harder than modeling the homeostasis of the climate.)
I am sarcastic because I am accustomed to hear a risible servility. But I am not attacking science. I trust that what has been declared a pseudoscience is so. In this retrospect science is indistinguishable from infallible. But I dispute the genteel hypocrisy which would pretend that pseudoscience has never entered the mainstream of science, or that if it ever had, it would have been due to outside meddling.
The fallacy, I believe, is called No True Englishman (Scotsman). "No true scientist would have participated in X; therefore any so-called scientist who participated in X was not a true scientist." The whole history of the relation of science and pseudoscience is constructed with this tautology.
True, science is not just a vocation, but an affiliation, a group, and therefore, like any other group, contaminated with loyalties and solidarities. But the more acute problem is that science and pseudoscience are not dichotomous. Degrees exist between them.
The world protoscience has been advanced for the pre-scientific pursuits that lead into sciences—as astrology leads into astronomy, as alchemy leads into chemistry, as doctoring leads into medicine. There may be many such intermediate degrees but I propose only one. Some scientific pursuits are neither sciences nor pseudosciences, but placeholder sciences. The textbook scientific method expects the succession, within a defined science, of observation, hypothesis, and theory. But in most scientific work the science itself is a hypothesis. The most common question is not, "What law governs this phenomenon?" but "Is this a phenomenon at all?"
Most ologies are not really fields at all, but gambits: in science a field does not arrive and then demand methods, subjects, a center and journals; rather the methods, subjects, the center and the journals are how hopeful scientists attempt to bootstrap a field into being. In the end the attempt either succeeds as a science, or fails as a pseudoscience; but in the meantime it is neither—it invites a science and clears a space for it, saves it seat. It is a placeholder.
For later scientists to judge a placeholder science according to its final result is unjust. The scientists who failed were not cranks; the scientists who succeeded were not visionaries. To suppose they could have known better in advance is to posit a faculty which, if it did exist, which make actual science superfluous. A scientist can no more anticipate a pseudoscience than a computer can anticipate a halting problem.
All sciences begin as gambits. The sooner this is recognized, the sooner we can avoid misplacing the faith due a mature science in its placeholder; but more importantly, the sooner this is recognized, the sooner we can begin, not just accommodating such gambits, but encouraging them.