To really get at why political science is so absurd, it really requires knocking Science TM off its perch. To many, it is palpable that they consider science as some abstract point of total truth that can be understood by all irrespective of opinions. This is false.
For everyone to agree on a point requires a base minimum of shared understanding of a given tradition to make that point meaningful. This greater context is always completely ignored in modern philosophy, of which science TM is a mere sub set.
Take the example of chemistry. How many differing models are there to explain molecular structures? How have they developed over time? and will they develop again in the future? The answer is numerous for the first question, greatly for the second, and undoubtably for the third. So if science keeps changing then its popularly accepted claims are without grounds. It is a tradition derived from a greater tradition of philosophy.
You can play this game with any scientific development (discovery is a bad word) and establish what its history was, what precepts had to be in place for this development, and how this development has been altered since. Zippy has some good ones regarding Darwin, but the same can be done with physics, chemistry, math, and every other area of science.
Like with Hobbes and Locke’ s thought experiment, the underlying assumption is that these points of science can be rationaly understood and comprehended by every person abstractly, but this is fraudulent. The whole thing rests on the giant error of these thinkers failing to grasp that this is a fallacy.
Just try it yourself with the strongest case you can, like Newton’s theory of gravity, which has been superceeded by Einstein, and which was a development of earlier theories. Then consider how Newton reasoned in a language and with thought patterns inherited from his society and used mathematical concepts and other concepts only understandable following an education.
If you think you have found an exception, then you haven’t widened your parameters enough, and are taking something as a given, which is not a given. Usually language for example.