I've been thinking this for awhile now. There are certain systems which are somewhat hazy or flubbery by nature. Legal and political systems fit into this category. Systems of logic and mathematics have more sharply delimited values for truth or falsity. Science is more sharply delimited, but even here, you see some of the haziness creep in. Is this particular grain of sand Ediacaran or Cambrian? There may be no way of saying, one way or another. However, that also isn't of particular import, one way or another.

Legal and political systems are particularly bad, since they tend to have very fuzzy distinctions combined with very significant consequences.