Those who wish to base their morality literally on the Bible have either not read it or not understood it.

The moral law is a reason to think of God as plausible - not just a God who sets the universe in motion but a God who cares about human beings, because we seem uniquely amongst creatures on the planet to have this far-developed sense of morality.

Religion teaches the dangerous nonsense that death is not the end.

Natural selection, the blind, unconscious, automatic process which Darwin discovered, and which we now know is the explanation forthe existence and apparently purposeful form of all life, has no purpose in mind. It has no mind and no mind's eye. It does not plan for the future. It has no vision, no foresight, no sight at all. If it can be said to play the role of the watchmaker in nature, it is the blind watchmaker.

Our brains have evolved to help us survive within the orders of magnitude of size and speed which our bodies operate at. We never evolved to navigate in the world of atoms.

Part of the appeal was that Medawar was not only a Nobel Laureate, but he seemed like a Nobel Laureate; he was everything one thought a Nobel Laureate ought to be. If you have ever wondered why scientists like Popper, try Medawar's exposition. Actually most Popperian scientists have probably never tried reading anything but Medawar's exposition.

You can never be absolutely certain that anything doesn't exist. But you can show that it's unlikely.