Quantitative work shows clearly that natural selection is a reality, and that, among other things, it selects Mendelian genes, which are known to be distributed at random through wild populations, and to follow the laws of chance in their distribution to offspring. In other words, they are an agency producing variation of the kind which Darwin postulated as the raw material on which selection acts.

An attempt to study the evolution of living organisms without reference to cytology would be as futile as an account of stellar evolution which ignored spectroscopy.

Man armed with science is like a baby with a box of matches.

Would I lay down my life to save my brother? No, but I would to save two brothers or eight cousins.

My practise as a scientist is atheistic. That is to say, when I set up an experiment I assume that no god, angel, or devil is going to interfere with its course; and this assumption has been justified by such success as I have achieved in my professional career. I should therefore be intellectually dishonest if I were not also atheistic in the affairs of the world. And I should be a coward if I did not state my theoretical views in public.

My final word, before I'm done, Is "Cancer can be rather fun"- Provided one confronts the tumour with a sufficient sense of humour. I know that cancer often kills, But so do cars and sleeping pills; And it can hurt till one sweats, So can bad teeth and unpaid debts. A spot of laughter, I am sure, Often accelerates one's cure; So let us patients do our bit To help the surgeons make us fit.

The advance of scientific knowledge does not seem to make either our universe or our inner life in it any less mysterious.