I suspect that any worthwhile exploration of these deep questions about living requires going beyond abstract discussions to the vivid presentation of possibilities. If readers are to be prompted to serious examination of their lives, anatomy isn't enough. We have to be stimulated to imagine, in some detail, what it would be like to live in particular ways.

So this is my attempt to give a preliminary - probably far too crude - account of how philosophy by showing can really teach us. The attempts we make to work through problems by reasoning always presuppose starting points, and even the most self-critical philosophers adopt some of those starting points simply by picking them up from the social environments in which they grow up.

The classical allusions and the Platonic disquisitions on beauty are no longer a form of cover, but integral to Aschenbach's complex sexuality. Moreover, the wandering around Venice in pursuit of Tadzio isn't a prelude to some sexual contact for which Aschenbach is yearning.

The point of philosophy, as I see it, is to change thinking, and thereby to change the conversation.

Sometimes, of course, the artist does give up, saying, in effect, "I've done enough". Prospero declares that the revels are ended, and breaks his staff - his author retires to Stratford. At the very end, Mann did something similar. Interestingly, in both instances, death came quite quickly after that.

In my current work on global warming, I argue that the only apparent solution to the deep problem of climate change would require very large transfers of wealth from rich nations to poor nations, so that the entire world can make the transition to renewable forms of energy as fast as possible.

I was occupied by a range of questions, often different from those fashionable in the professional philosophy of the past half century, that have sometimes troubled philosophers in the past. It's taken me several decades to work out my own philosophical agenda, and it is wide.