Political theory is not only political thought but also consists philosophy.  Few scholars incorporating that political theory is a science and they called it Political Science.  Political philosophy uses scientific methods of analysis of the political theories.  Any speculative thesis that is proposed by political philosophy can be part of scientific political theory only as a “working hypothesis”. Political theory is not a history, but it is history in the limited sense. It is  philosophy in some degree; It is science so far as it responds to reason. A political theorist has to be a part historian, a part philosopher, and a part scientist.  Political theory without history is a structure without a base. It loos its base & significance without history. In study of politics, we learn to understand political tradition. As history, political theory conserves what has significance and helps posterity to cherish it for a long time to come. Concepts such as justice, liberty, equality, obligation, as evolved through the annals of time, are being held high by political theory today and shall continue to be so in future.  

Political Theory As History : Political theory is history in the sense that it seeks to understand the time, the place and the circumstances in which it evolves. If it ignores its historical context, it loses its strength, its focus and its message. Any political theory has to have facts as the basis, circumstances in which it develops, and the message, i.e., political theory. Political theory is not merely/only history, it is a science in so far as it is not understood in isolation, and also a philosophy in so far as it motivates. 

Political Theory As Philosophy : The political theory is a philosophy but all philosophy is not political theory. Philosophy, as an abstract study encompassing the whole universe in general, and morals, norms, and values in particular, is the sum-total of general laws governing the whole world. Political theory is a philosophy, for it not only seeks to know the nature of things but also attempts to explain as to why things really exist. One understands an action or a thought only by evaluating it. Evaluation is a part of understanding. 

Political Theory As Science : The political theory is a part of science but is not a science. Political theory is not only science as there are no universally recognised principles, no clear cause-effect relationships, no laboratories and no predictions are made in political theory the way these are found in natural and exact sciences. It is a science in so far as it admits concepts and norms which are both observable and testable, and in so far as it responds to the requirements of reason and rationalism.