Pharyngula recently provided a definition of science. While this may seem a rather boring point to pore over, I found myself spending a lot of time thinking about this over the weekend, and I found it exhilarating:
#1: Science is a changing and growing collection of knowledge, characterized by transparency (all methods are documented, and the lineage of ideas can be traced) and testability (prior work can be repeated or its results evaluated). It is an edifice of information that contains all of the details of its construction.I'm going to assert that he missed one very useful definition. Or at least one very important point. Science demands proof. Science requires that its practitioners provide proof for their hand-waving, otherwise you are merely spewing words. If you cannot provide an iron-clad experiment that demonstrates the point you are trying to make, then you are merely working at conjecture.
#2: Science is what scientists do. We have institutions that train people and employ them in the business of generating new knowledge — contributing to that edifice in definition #1 — and we have procedures like the bestowal of degrees and ranks that certify one's membership in the hallowed ranks of science.
#3: Science is a process. It is a method for exploring the natural world by making observations, drawing inferences, and testing those inferences with further experimentation and observation. It isn't so much the data generated as it is a way of thinking critically about the universe and our own interpretations of it.
I think this is the most important point for laypeople to understand. How is someone to tell the difference between a scientist who knows what (s)he's talking about, and a pseudoscientific quack? I suspect for your average, college-educated person this isn't simple. A scientist may use technical words that are difficult to understand. A pseudoscientific quack may use technical words that are difficult to understand. A scientist may talk about the importance of molecules in their work. A pseudoscientific quack may talk about the importance of molecules in their work. But how do you tell the difference between a highly-talented medical researcher, and a pseudoscientific quack like Hulda Clark? Demand proof.
If someone tells you that worms cause all cancer? Demand the experiment that proves it.
This is the single reason why highly opinionated, egotistical scientists can emerge from a room with a consensus. Unlike in law, or philosophy, or business, or politics, scientists can change each other's minds using proof. That said, for any honest scientist, they can have their minds changed merely by providing experimental evidence that they are wrong.
This is why Carl Sagan says:
"Science is more than a body of knowledge; it is a way of thinking. I have a foreboding of an America in my children's or grandchildren's time ... when awesome technological powers are in the hands of a very few, and no one representing the public interest can even grasp the issues; when the people have lost the ability to set their own agendas or knowledgeably question those in authority; when clutching our crystals and nervously consulting our horoscopes, our critical faculties in decline, unable to distinguish between what feels good and what's true, we slide, almost without noticing, back into superstitions and darkness."This is what gives science the power to discern truth from bullshit. This is why science is a candle in the dark. This is why scientists feel so passionately about their work. Science offers us the opportunity to say, "Prove it!" and have some possibility of doing just that.