What is the difference between political theory and political science?

As philosophy seeks to establish the ethics of a particular subject, it deals with what should be,---sustainably idealistic in a given situation.Political philosophy,thus,seeks to underline the moral discipline that politics has to abide by in a sustainable way.

Science,on the contrary,seeks to prove a thing by experiments and analyses and declare it established,-----the pursuit having nothing to do with the ideal, as such. Political science is,therefore, concerned about the proved growth of the polity without having to bother about its evolution in the desired idealistic direction.

The difference betwen the two may be summed up as:the former in establishing a theory looks to 'what should be', and , the latter to 'what is'.