[Q] Your retiring address as President of the Royal Society was widely reported, both in the daily papers and in learned journals, where you criticise decades of government spending in defence. Is this an issue on which you feel very strongly and were saving up for this occasion?

Well in some sense, I suppose, I feel fairly strongly on that and related issues. When I was… all the time I was president I would make comments somewhat along those lines, but in more muted form. But I discovered after a while that if you make comments in muted form, people don't pay any attention to them. You don't get the headlines if you, sort of, carefully circumscribe your statements in a good academic sense. So my last year, I thought I should actually be a bit more forthright and so I said things which I've thought of before, but… in order to perhaps to attract a bit of more public attention. And so in that sense it succeeded, it did... it did actually. And of course once you break through the barrier of getting reported somewhere, it tends to, you know, it tends to sort of build up. And so in fact, I’ve got… subsequent to that I've got more involved... more involved with those issues. People ask me to do… give talks here.  I’m giving a talk at Imperial College, you know, in a couple of weeks time. I've got a bit more involved with the Pugwash movement, which I went to their meetings in Finland last year, I'm going to their meeting Norway this year.

And so you... you… if you come out openly with things of that kind, then of course you... you get… attract the attention of people who want your help to carry that sort of line forward. So I've... I’ve… well I asked for it if you like by saying those things, I have to sort of keep following them up. So I’m... I’m… and I think I… one thing I've learnt all through my life I suppose is that... is that, I start... I start off being fairly sort of cautious as an academic, you know, most academics tend to be. You know that life's complicated, you don't think… you know it's not simple, and so I tend to take a… be a little bit cautious about what I say and not being extreme. And also you tend to be not so self-confident that you're right. You know, a scientist knows that there are two sides to things and you don't know all the… so I tend not to be overconfident about my own understanding of things. But the more I've gone on I've realised that other people actually go around making statements based on even less experience. So I've acquired the kind of necessary confidence to... to override that.

I think I now probably know as much as many other people and – on certain issues – and I... I feel that therefore it's incumbent on me to say so, not leave the field open to those who actually go round with less information claiming to be experts. So I think that's the kind of thing you… in general within the universities and outside… I've become more confident in my own assessments of things, whether it be mathematics or science or other things. Initially I was always rather tentative, I would defer to other people's views with the more experience; I now realise that was perhaps a mistake. And so I now try to actually follow that up and... and speak my mind and write my views more… with more confidence than I did, you know, 20, 30 years ago.