I'd also like something that is more frequently used in the context of politics than the given example of 'viscosity.' Therefore the word(s) I'm looking for connotes something like ' intentional viscosity.' It should be easily understandable and would ideally require no explanation. The shape of the law can and does change, but only very slowly. However, I think it's useful to think of the legislative process as neither an immutable solid nor a watery liquid, but rather a very viscous liquid.

The normal use of viscosity has nothing to do with legislation. In case it helps, when I think about the first aspect, I think about viscosity. The intentionality of this design (the slowness is a feature, not a bug)

I'd like an alternative for 'intentionally slow.' I'm looking for one adjective (a short phrase would be acceptable, but not preferred) to express two important aspects: Changing a law is supposed to require significant thought, deliberation, and justification. It was designed that way so that laws could be changed, but not capriciously. In the U.S., it's often said that the legislative process is intentionally slow.

What is another word for slow