Rationality is the opposite of science You must be much more careful when speaking of rationality. When you say, “Then rationality came along and pointed out that meanings can’t be objective, there are no spooks, and you can’t derive ought from is,” you’re mixing critiques of rationality (meanings can’t be objective & can’t derive ought from is) with rationality. When you mention science, you’re promulgating the myth that rationality is scientific thought. Rationalism is an ancient philosophical tradition. It is basically Classical Greek thought, e.g., geometry & Aristotelian logic. It is axiomatic and Boolean, and operates on atomic symbols which map directly to eternal concepts. It specifically denies the validity of empirical experiments. It operates only with integers. Its physics is based on static analysis. It denies the existence of infinities or infinitesimals, and so can never understand change–which it doesn’t really believe in, deep down, as it is a type of eternalism. Scientific empirical thought was historically considered the opposite of rationalism. It says that we should look to the material world for understanding, that language is nominalist, that terms should not be defined but operationalized, and we can construct concepts as labels of statistical abstractions, that truth is statistical, that proper syntax does not guarantee meaning. It replaces Aristotelian logic and physics with real numbers, infinitesimals, differential equations, and probabilities. The entire post-modern attack on reason is based on getting people to pretend that science never happened, that science is actually medieval metaphysics and our only choices are Aristotelianism or unreason.