I don't feel proprietorial about the problems of philosophy. History has taught us that many philosophical issues can grow up, leave home and live elsewhere.

If there's one thing that makes me cynical, it's optimists. They are just far too cynical about cynicism. If only they could see that cynics can be happy, constructive, even fun to hang out with, they might learn a thing or two.

It may not have the virtuous ring of the golden rule, but the maxim "never say never" is one of the most important in ethics.

The optimist underestimates how difficult it is to achieve real change, believing that anything is possible and it's possible now. Only by confronting head-on the reality that all progress is going to be obstructed by vested interests and corrupted by human venality can we create realistic programmes that actually have a chance of success.

Even if we can agree that some things are natural and some are not, what follows from this? The answer is: nothing. There is no factual reason to suppose that what is natural is good (or at least better) and what is unnatural is bad (or at least worse).

Happiness is not the same as life satisfaction, while neither are identical to what we might call flourishing.

We can take suffering to be an opportunity to learn and to grow. But if we are honest, we should remember that this is making the best of a bad job, and that minimising suffering takes priority over optimising its outcome.