A common accusation leveled against science by its enemies is that it is too closed-minded, too dogmatic, too authoritarian. From creationists to "alternative medicine" advocates to New Agers, the defenders of pseudoscience argue that science is closed to new ideas, set in its ways, unwilling to challenge conventional wisdom. If only science would examine our claims with an open mind, goes the refrain from each fringe community, they would see that they are fully deserving of inclusion.
There is a fundamental error in this type of claim, one which turns on a misunderstanding of what science truly is. All these claims assume that what science is, first and foremost, is a body of knowledge, a catalogue of facts about the world, and that admittance to this list is what makes an idea scientific. All it takes, they think, is to overcome the dogmatism of the gatekeepers.
The error in thinking this way is that science is not a body of knowledge, at least not primarily. Instead, I would argue that science is primarily a way of knowing, a particular way of looking at and investigating the world. The knowledge gained by this method can also be considered science, but only in a secondary sense. Being aware of this body of knowledge is not a necessary prerequisite to do science. Being in the habit of looking at the world in a scientific way is.
This is where defenders of creationism and other pseudosciences go wrong. They assume that there are no particular criteria for an idea being scientific, other than acceptance by scientists or by society at large. In fact, an idea can only properly be considered scientific if it is a product of this particular way of thinking - the scientific method - from beginning to end. "Science" is not a label that can be slapped on just any finished idea, but is an intrinsic aspect of the way that idea was brought into being and developed.
What is the scientific method? A full description is well beyond the scope of this post, but the simplest summation is to say that an idea developed using the scientific method has two vital qualities: it should be testable and tested. An idea is scientific if and only if it makes definite and checkable statements about the way the world should be, and those statements actually have been compared to reality and verified to be true by independent investigation.
An idea fails the first criterion if it makes no predictions at all, or if those predictions are so vague or subjective that there is always an escape hatch for any test claimed to disprove them. An idea fails the second criterion if it has never been put to the test, or if it has only been put to the test by self-interested investigators who have an incentive to cover up or rationalize away any failure, or if it has been put to the test and has failed.
But there is slightly more to it than that: there is a particular sort of attitude, a way of conceptualizing and reacting to the world, that goes hand-in-hand with formulating testable ideas and then testing them. Doing science means being skeptical: neither dogmatically rejecting nor credulously accepting every new idea, but maintaining a "wait and see" attitude until that idea has proved itself against the evidence. A wise scientist proportions their skepticism to the extraordinariness of the idea, requiring a stronger threshold of proof for an idea that contradicts a greater number of other ideas that have been tested.
Doing science also means a scrupulous intellectual honesty, a free and open attempt to rule out all possible sources of error that can be ruled out, and a full and forthright disclosure of the ones that could not. A good scientist will not be a diehard advocate of their own idea, but will, as best as they can, consider it in the same spirit of neutrality that anyone else would, and if at all possible will suggest tests by which it can either stand or fall and accept the results whatever they may be. A good scientist will listen to and carefully consider the counsel of others, and will consider the people who attack their own ideas most fiercely to be their most valued allies. And a good scientist will never consider any conclusion to be immune from further challenge, no matter how old or venerable it is.
People who view science as an arrogant, overbearing authority are wrong. In fact, anyone can be a scientist. It doesn't require an advanced degree or expensive equipment, only a thinking mind and a willingness to investigate the world. Indeed, that is why science is so useful. The homemaker who plants flowers of the same species in various places in a backyard garden to determine what combination of sunlight, shade, soil and water is best for them is no less a scientist than the physicist studying the building blocks of matter in a massive, multimillion-dollar particle accelerator. Though the ideas being studied differ in degrees of complexity, the approach is the same.
In general, practicing scientists scorn advocates of pseudoscience not because they are stuck in their ways, but because these people refuse to play by the rules. In most cases, they either have no knowledge of or actively reject the scientific method, and then expect their untested, untestable ideas to be accepted into the scientific canon and accorded equal respect along with the ideas that have been laboriously, painstakingly tested by hundreds of scientists over many years.
If anyone is excluded from the scientific community, it is by their own choice. If you disagree with the conclusions scientists have reached, do not stand on the sidelines griping and complain of dogmatism when your idea fails to be accepted purely on your say-so. Instead, roll up your sleeves and get to work. The history of science is full of ideas that were not accepted at first and became conventional wisdom only after their advocates could produce the hard evidence supporting them. If you can do the same, scientific fame and glory await.