In this article, I am going to point to some trends in the Japanese post-war political thought on the side of government (as opposed to electorate and political parties). I am going to analyse all the policy speeches held in the Diet during the last fifty eight years of all the prime ministers from Katayama to Koizumi. I am going to show how three main groups of prime ministers arise and discuss their characteristics. I will make an attempt to see the prime ministers of the LDP and of non-LDP in the traditional framework of left――right or conservative――social democratic scale and show why this bares no fruit. Finally, I am focusing on Koizumi and discuss in what terms he stands out from all the other prime ministers in his rhetoric.