I FIND myself playing a game in which I try to deduce from his speeches what job Tony Blair wants to do after he leaves Downing Street. A few weeks ago I was sure that a grand overview of world affairs meant he had his eye on being the next Secretary General of the United Nations when Kofi Annan leaves at the end of this year. But yesterday his speech on crime punishment at Bristol gave me the distinct impression that what he really wants to do when the day comes is to run a Think Tank. The speech was billed as the first of a series in which Mr Blair will look at the big issues facing Britain and the world and one phrase from it confirmed my impressin: “I have come to the conclusion that part of the problem in this whole area has been the absence of a proper, considered and intellectual debate about the nature of liberty in the world...We desperately, urgently need a rational debate from first principles.” Of one thing Mr Blair can be quite sure. There is absolutely no chance of having “a rational debate from first principles” anywhere near the House of Commons or Whitehall where knee-jerk reactions to find “headline-grabbing initiatives” (Mr Blair's phrase from long ago) are the order of the day. Perhaps not a Think Tank, after all. The Vice-Chancellorship of one of the older universities would be just the ticket.