This book by Paul Feyerabend is one of the most important and certainly the most radical books of philosophy of science to come out of the twentieth century. It forms almost a perfect sequel to Thomas Kuhn's book in the same field - only, where Kuhn gave us an objective "what happens and how" of revolutions in scientific fields, Feyerabend here gives us a more subjective "what could maybe happen, and how to do it". To use a comparative metaphor, Kuhn wrote of scientific revolution like Marx wrote of its socio-economic equivalent, while Feyerabend writes of it like Che Guevara, chock full of grassroots incitement to properly-informed action and ample tactical advice (using Galileo's career as prime example).
I won't go into depth with a summary of what he talks about in this book as it spans a huge arena of the history of science, its present and future capacities, and the dynamics at play in determining what we may consider progress in all of this. To give a very brief summary of the main point of the text though, I will say that Feyerabend sees the only sustainably trustworthy epistemological approach to science as that of anarchism. That is to say, when approaching theory, fact, experiment, and so on, the only reasonable guideline to guarantee that progress can intuit itself into the field's grasp on its object is: "anything goes." I like this a lot. It's a healthy reminder that even the most open-minded empiricists can, and do, get bogged down in the accumulation of the best thinking of all the open-minded empiricists who came before them, and thus often cease being effective open-minded empiricists. Epistemological anarchism is an approach that rightly inspires terror in the hearts of academics who have devoted their careers to the minutiae of issues under particular paradigms; however as an approach deigning to liberate and guarantee the continual advancement of any kind of knowledge, it's very difficult to argue with given how unpredictable are the paradigm shifts in any given field of study.
If you're interested in the philosophy of science I'm going to assume that you've already read this, but if you're merely a scientist who has given relatively little thought to the epistemological conditions of your work, I'd highly recommend this if you want a revolutionary energising shock.
