In the following items, each passage consists of six sentences. The first sentence (S1) and the final sentence (S6) are given. The middle four sentences in each have been removed and jumbled up. These are labelled P, Q, R and S. You are required to find out the proper sequence of the four sentences and mark accordingly on the Answer Sheet. 

S1: Man's growth from barbarism to civilization is supposed to be the theme of history. 
P: Strong countries attack and oppress weaker ones. 
Q: But it is difficult to believe this ideal has been reached. 
​R: There is ample evidence of barbarism even today. 
S: Individuals too exploit their fellows. 
S6: In many ways, therefore, man has not made very great progress.