Without imagination we can go nowhere. And imagination is not restricted to the arts. Every scientist I have met who has been a success has had to imagine.

Today mythical thinking has fallen into disrepute we often dismiss it as irrational and self-indulgent. But the imagination is also the faculty that has enabled scientists to bring new knowledge to light and to invent technology that has made us immeasurably more effective.

A writer should have the precision of a poet and the imagination of a scientist.

Now science has presented us with a hope called stem cell research which may provide our scientists with many answers that have for so long been beyond our grasp.

As great scientists have said and as all children know it is above all by the imagination that we achieve perception and compassion and hope.

One thing that being a scientist has taught me is that you can never be certain about anything. You never know the truth. You can only approach it and hope to get a bit nearer to it each time. You iterate towards the truth. You don't know it.

I seem to be thinking rationally again in the style that is characteristic of scientists. However this is not entirely a matter of joy as if someone returned from physical disability to good physical health.

As it turns out social scientists have established only one fact about single women's mental health: employment improves it.

When the honour is given to that scientist personally the happiness is sweet indeed. Science is on the whole an informal activity a life of shirt sleeves and coffee served in beakers.

Scientists dream about doing great things. Engineers do them.