The chief trick to making good mistakes is not to hide them-especially not from yourself.

If you can approach the world's complexities, both its glories and its horrors, with an attitude of humble curiosity, acknowledging that however deeply you have seen, you have only scratched the surface, you will find worlds within worlds, beauties you could not heretofore imagine, and your own mundane preoccupations will shrink to proper size, not all that important in the greater scheme of things.

We need to let our children grow up to face the world armed with knowledge, with much more knowledge than we ourselves had at their age. It is scary, but the alternative is worse.

Up till now, we can suppose, nervous systems solved the 'Now what do I do?' problem by a relatively simple balancing act between a strictly limited repertoire of actions - if not the famous four F's (fight, flee, feed, or mate), then a modest elaboration of them.

We should get used to the idea that we'll probably never be able to find - and confirm - a good explanation of the ultimate origin of the universe, though I see no reason to believe that we can't press much further on this question than we have managed to date.

Is he a dread genetic determinist, or a dread environmental determinist? He is neither, of course, for both these species of bogeyman are as mythical as werewolves. By increasing the information we have about the various causes of the constraints that limit our current opportunities, he has increased our powers to avoid what we want to avoid, prevent what we want to prevent. Knowledge of the roles of our genes, and the genes of the other species around us, is not the enemy of human freedom, but one of its best friends.

Sometimes you don’t just want to risk making mistakes; you actually want to make them - if only to give you something clear and detailed to fix.