I am incrementally a pessimist, but I see the international debate that Edward Snowden has engendered, and I think this is exactly where the discussion should be. So, I would say I'm more optimistic than pessimistic.
I think revolution is always a little bit possible. I think it won't look or sound anything like what we would expect. But I think revolution is very difficult, and I'm not optimistic for any kind of dramatic change.
Except when you're marching to war, it's not a very optimistic thought, is it? In other words, it's the opposite of optimistic when you're thinking you're going to war.
It's no wonder that America's engagement in the region has strong, sustained, bipartisan support. So I'll be handing my successor a strong foundation - including closer ties with Singapore - on which to continue building, and I'm optimistic that will happen.
Cuba is actually one where I am more optimistic because of the unique nature of Cuba - 90 miles off our shore with a massive ex-patriot population, now Cuban-American population that still have deep links to the island. There I am more confident that over time that the winds of commerce and telecommunication and travel start shifting the nature of that regime. But that's a small country which has almost a unique relationship to us.
We should cultivate the optimistic temperament, and endeavour to see the good that dwells in everything. If we sit down and lament over the imperfection of our bodies and our minds, we profit nothing; it is the heroic endeavour to subdue adverse circumstances that carries our spirit upward.
Our thoughts really do create our lives. They've done a lot of research showing if you're an optimistic, positive person you will be a healthier person than if you're a sad, depressed, negative person.
And I am an optimistic person. I guess if you want to try to find something to be pessimistic about, you can find it, no matter how hard you look, you know?