I reckon your wrong about political science and well most of your post. Next time I recommend getting familiar with what academic work already exists to answer your question of interest. Political science can be desciptive, which is useful too. It doesn't have to be normative.

• Economics - how are and should scarse resources be distributed
• Psychology - how does and should the mind work
• Medicine - how does and should the body work
• Politics - how does and should politics work
• Business - how does and should business works.

Things are organised basically like that - description and prediction.

Etc etc. The question of boundaries between these fields of relicted to the history and philosophy of science. Historiographers have looked into it but it's largely academic now.