DSeid: to most of your questions and points, yes-yes-yes.
Yes, I do think that the label of “science” is often arbitrary on many levels. Often we apply it to areas which we “feel” are scientific, then retroactively or regressively try to explain why this area is science, that is not. Does that mean I think that the scientific method is useless? No. Does that mean I think that it is limited? Yes. The fact that we, with our finite human brains, cannot imagine a way to explain some aspect of the Universe according to a set of particular rules (the scientific method) does not mean that the aspect can be dismissed, or is unreal. It simply means that these rules do not apply to every phenomenon in the Universe. To think otherwise is arrogance. Does this mean I am uncomfortable with a definition of science which draws rigid lines between this and that? Yes.
Rather than defining science as a thing itself, I propose the following. Consider this a thought-experiment rather than a manifesto, and please excuse any generalizations or over-simplifications I seem to make, and try to see the overall thrust of this thought-experiment.
First, recall that in English the word science is derived from the Latin scientia, the most basic meaning of which is “knowledge”. That is, the basic meaning does not carry around all that baggage it has accumulated since the European Renaissance. I’d like to attach that basic idea of “knowledge” to all of those areas which have been, until now, labelling “science”, “non-science”, “proto-science”. So instead of thinking about “science”, let’s instead think about human endeavors which deal in knowledge.
Now, for several centuries we’ve had this catchy, useful philosophy in circulation called the scientific method. This is an unfortunate name because it implies that “this is the way to acquire knowledge” and so seems immediately exclusive. Instead, let’s call it the Baconian method. Granted, he wasn’t the first/only person to adopt this approach, or parts of it, but he was the first to express it in writing for posterity. Also granted, that other thinkers helped to fine-tune the approach, but his basic thinking is still what defines this method. The Baconian method was very useful for understanding and explaining the natural world – the world accessible to the five human senses. It was attractive because it did so in a way and to a level of detail which other philosophies, such as mysticism or a particular religious mythology, had not been able to do. This was very satisfying to the human mind during a time (in Europe) when humans had started to believe that Earthly existence was just as important as any afterlife, that human thought and culture and expression were intrinsically meaningful, that the way human beings looked at the world was important. And so the Baconian method caught on, to varying degrees, in many areas of knowledge. It was eminently suited to explaining the natural/physical world – the world experienced with the human senses – because this method was predicated on the idea that the human senses were a good way to gather information. (Unlike the approach of, say, Aristotle, who tried to explain the world without interacting with it.) Of course, the Baconian method included other precepts about how one uses and interprets information so gathered, so that, in other areas of knowledge which could not or did not gather information the same way, the Baconian method was less useful. Not entirely useless, mind you, but it had its limits. For instance, the method could be employed in the study of history to set standards of “evidence” for historical events and phenomena, but history did poorly when it came to predicting future events. But this is true for any philosophy: it is useful in some areas, less useful in others.
In time, the significance of human life, culture, expression, Earthly existence became hallmarks of “Western” civilization. Along with them came an emphasis on the importance of the natural, physical world – the “real world”, so to speak. This placed those who practiced the Baconian method, in areas of knowledge concerned with the natural world, in an admirable and enviable position. Eventually these practitioners forgot (or ignored) the fact that their method just happened to be a good one for one subset of human knowledge and came to label their area(s) of knowledge science because they were able to employ the Baconian method most thoroughly and rigorously. Other areas of knowledge, which could not apply the method so rigorously, were not called science, or at least not thought of as being quite in the same company. They may have been considered scholarly, but not scientific.
In time, too, people began to build devices which, in effect, extended the human senses by measuring things more precisely than the senses alone. An increasing understanding of the physical world allow the construction of machines to accomplish amazing tasks. Along comes the Industrial Revolution. This is another happy development for the soi-disant scientists: these machines offer insight into the physical world beyond that accessible to normal human senses, allowing greater understanding of the world and the construction of increasingly complex machines in a never-ending cycle of progress. And civilization is indebted to these so-called scientists because all of this is built, primarily, on their particular areas of knowledge.
And so down to the present day, where those rigorous practitioners of the Baconian method (or so they claim) decide, in effect, that “anything which does not follow our method to the letter is not science”. But in the present day, there are so many different fields of knowledge, and so much communication, overlap and cross-fertilization between them, that this assessment doesn’t “feel” right to some scholars. Why does it matter, though? Why don’t these scholars just shrug and say, “So what if my area of knowledge isn’t science?”
Because in the 20th-century Western world, the self-defined body of knowledge called science became, in a sense, a new religion. At the very least, it is held in awe, the pinnacle of human achievement, something with a desirable cachet.
My definition? Well, in case you hadn’t guessed, it goes something like this: There is no such thing as science, per se. The original meaning of that word, in English, is far too corrupted, too loaded, for it to be used in a neutral way. So, depending on how rigorously and completely the Baconian method can be (or is) employed in a particular area of knowledge, that area is classified as more scientific or less scientific. There is very little white, very little black, mostly shades of grey.
So, is chemistry science? No. Is it scientific? Yes, very much so. Does this entitle it to a place of superiority among the fields of human knowledge? No.
Is the study of history science? No. Is it scientific (or can it be)? Yes, because the basic premise of what constitutes valid evidence, for or against a particular hypothesis, carries over from the Baconian method very nicely. On the other hand, the idea of generating predictions about the future from theories doesn’t fly too well, and in any case history doesn’t pretend to these kind of predictive powers.
Are psychology, and related fields, science? No. Are they scientific? Perhaps more so than history (I don’t know enough about psychology to rank it against history!), but decidedly less so than chemistry, for reasons pointed out by Demosthenesian above: "A human mind is, ironically, in many respects a much tougher system to understand than the ones that allow it to exist."
Is astrology science? No. Is it scientific? Well… some say to a degree it is, others say absolutely not. The problem here is that astrology is usually measured against psychology to determine whether it is scientific. But psychology does not lend itself to a rigorous application of the Baconian method. So what makes it a good yardstick against which to measure how well other areas employ the Baconian method?
Here endeth the lesson.
Jerevan