Unfortunately we were not able to come to an agreement on "What Is Science."
Now we have to meet again in a couple of weeks!
We talked about whether there was a scientific method and whether falsifiability is part of the definition of science. The Wikipedia article on falsifiability is a good place to look for background information. Here are two sections from that article to get you started.
Paul Feyerabend examined the history of science with a more critical eye, and ultimately rejected any prescriptive methodology at all. He rejected Lakatos' argument for ad hoc hypothesis, arguing that science would not have progressed without making use of any and all available methods to support new theories. He rejected any reliance on a scientific method, along with any special authority for science that might derive from such a method. Rather, he claimed that if one is keen to have a universally valid methodological rule, epistemological anarchism or anything goes would be the only candidate. For Feyerabend, any special status that science might have derives from the social and physical value of the results of science rather than its method.There's no such thing as a universal scientific method and falsifiability doesn't describe how the scientific way of knowing actually works.
In their book Fashionable Nonsense (published in the UK as Intellectual Impostures) the physicists Alan Sokal and Jean Bricmont criticized falsifiability on the grounds that it does not accurately describe the way science really works. They argue that theories are used because of their successes, not because of the failures of other theories. Their discussion of Popper, falsifiability and the philosophy of science comes in a chapter entitled "Intermezzo," which contains an attempt to make clear their own views of what constitutes truth, in contrast with the extreme epistemological relativism of postmodernism.
Sokal and Bricmont write, "When a theory successfully withstands an attempt at falsification, a scientist will, quite naturally, consider the theory to be partially confirmed and will accord it a greater likelihood or a higher subjective probability. ... But Popper will have none of this: throughout his life he was a stubborn opponent of any idea of 'confirmation' of a theory, or even of its 'probability'. ... [but] the history of science teaches us that scientific theories come to be accepted above all because of their successes." (Sokal and Bricmont 1997, 62f)
They further argue that falsifiability cannot distinguish between astrology and astronomy, as both make technical predictions that are sometimes incorrect.
I made up an example of a Professor of English whose research focuses on how the English language actually sounded in the time of Geoffrey Chaucer (about 1370)¹. Is she doing science? If not, what kind of way of knowing is she using?
1. This is roughly the time of World Without End. If the characters actually spoke in 14th century dialect we probably wouldn't have understood a word.