The question below consists of a set of labelled sentences. Out of the four options given, select the most logical order of the sentences to form a coherent paragraph.

P- Epistemological idealists (such as Kant) might insist that the only things which can be directly known for certain are ideas. 
Q- The approach to idealism by Western philosophers has been different to that of Eastern thinkers.
R- In much of Western thought (though not in such major Western thinkers as Plato and Hegel) the ideal relates to direct knowledge of subjective mental ideas, or images.
S- It is then usually juxtaposed with realism in which the real is said to have absolute existence prior to and independent of our knowledge.