The right to choose to live or to die is the most fundamental right there is; conversely, the duty to give others that opportunity to the best of our ability is the most fundamental duty there is.

I dont often meet people who want to suffer cardiovascular disease or whatever, and we get those things as a result of the lifelong accumulation of various types of molecular and cellular damage.

It's not just about life, of course; it's about healthy life. Getting frail and miserable and dependent is no fun, whether or not dying may be fun.

What I actually wanted to do with my life is make a difference to the world. That led me into science very quickly.

Ageing is, simply and clearly, the accumulation of damage in the body. That's all that ageing is.

My approach is to start from the straightforward principle that our body is a machine. A very complicated machine, but none the less a machine, and it can be subjected to maintenance and repair in the same way as a simple machine, like a car.

I think it's reasonable to suppose that one could oscillate between being biologically 20 and biologically 25 indefinitely.