- For example, rules such as adopting the most widely accepted theory or denying theories that are incompatible with generally accepted facts wouldn't have done possible most important scientific changes in history to happen.

- This is the only rule that doesn't constrain imagination and creativity, and therefore, the appearance of new hypothesis and theories: principle of proliferation.

In words of Godfrey Smith “Feyerabend's deepest conviction was that science is an aspect of human creativity”, thus, we could maybe understand it as a kind of art, another attempt to fill the gap between desire and ordinary communication.

- While for most philosophers Kuhn was a dangerous irrationalist, for Feyerabend was the contrary: he was maybe the only one on interpreting his intentions properly, as he meant to give a solid ground for science to be understood as a completely rational and logical epistemological process.

Of course Feyerabend saw his philosophy “as encouraging the worst trends in twentieth century science towards professionalization, narrow-mindedness, and exclusion of unorthodox ideas”.

- Two (or more) rival theories are incommensurable if they are so extremely different that there is no way to compare them logically; the basis and concepts on those theories don't coincide, so they will be incommensurable.

- Nevertheless, there are, indeed, another ways to compare those theories, for example, confronting each one to a concrete situation and checking which one is the most valid in this case. However this would only let us choose between both in that unique situation.

- Ptolomeo's astronomical theory is still valid inside its own limits: we use it in our calendars, and although it has some maladjustments it's still useful.

- But if we have to choose the criteria to compare rival theories, we have the same problem: we just can't decide which criteria is better, it will depend, of course, in the context. Incommensurability leads, in the end, to a necessarily subjective aspect of science.

- But, continuing in this path of incommensurability, Feyerabend claims there's no decisive argument to believe in such status of science.

- By this argument, Feyerabend defends the “humanitarian attitude”, based on Stuart Mill's concept of liberty.

- So, the institutionalization of science is incompatible with the “human attitude”. According to him, science should be studied as another historical fact, similar to fairy tales and myths, so that everyone will have enough information to reach a free decision.