Didn't realize we had a new thread already. Oh well.
Paul Feyerabend's Against Method (2010 edition, Verso) insists that in science, "anything goes". The contents of the chapters are summarized in a plain-language "analytic index" at the beginning. It rejects the consistency condition (new hypotheses must agree with accepted theories) and the autonomy principle (facts are independent of theories and their alternatives), and calls for counterinductive approaches where new theories clash with older ones. This is mainly illustrated through an investigation of how Galileo fought for an heliocentric worldview. The rest of the book is concerned with the idea of incommensurability (incompatibility of worldviews through suspension of principles) through various comparisons, most significantly of paratactic aggregates (supposedly the archaic view in which many things, even people, are assemblages of parts with equal intrinsic significance that enter into external relations) with the substance-appearance philosophy (as with Plato's Forms, where the sense world is not the full picture). The overall conclusion of the book is that science is not the only way to truth and that the strong enforcement of rules stifles progress. Feyerabend does not reject the scientific method, but insists that there are multiple such methods and they should be guided by humanistic principles that do not prefer one system of values to another.
The book has some issues, potentially one of which is the time of writing. The first edition came out in 1975, and the next editions don't really change much. There is a section where the Communist Party of China is praised for emphasizing Traditional Chinese Medicine in 1950s. Before the Cultural Revolution. The book is also heavily physics-focused and mainly relies on Galileo's example, calling into question the generality of the principles espoused. Various field of genetics were able to flourish after all despite the lack of recent major revolutions in biology. This leads to the issue of the book acting like a mere extension of Kuhn's Revolutions, i.e. a closer investigation of the generation of new hypotheses that generate paradigm shifts. Feyerabend differs in some aspects (e.g. old theories not being overthrown), but he has nothing to offer regarding so-called normal science. The book does not even consider the technical and material aspects of conducting modern science. "Let a Hundred Theories Blossom", he says, while ignoring how hard it is to book time on expensive telescopes, light sources, and accelerators. There is nothing in the book to rule out pseudoscience like antivaxxers, climate denialism, or Time Cube. Feyerband is also fond of saying outrageous things like how scientists want to impose rules on society. Occasionally he contradicts himself, like how he complains about science in one chapter, treating it as a monolithic beast, and then emphasizes the diversity of the sciences in another. To his credit, Feyerabend admits the book wasn't conceived in a systematic way in the last chapter where he lists his various influences.
Despite all that, it is a book definitely worth reading and analyzing. It has taught me the value of reading old scientific texts like that of Aristotle. What is old may become new again, as Galileo's example shows. Especially in physics, where it seems to be in crisis, as The Trouble with Physics illustrates, the text that introduced me to Herr Feyerabend.