A pinch of probability is worth a pound of perhaps.

Boys are perhaps beyond the range of anybody's sure understanding, at least when they are between the ages of eighteen months and ninety years.

Now I am not a cat man, but a dog man, and all felines can tell this at a glance - a sharp, vindictive glance.

'Who are you?' the minstrel asked. 'I am the Golux,' said the Golux, proudly, 'the only Golux in the world, and not a mere Device.'

You should never bet against anything in science at odds of more than about 10 or 12 to 1.

Life in the twentieth century is like a parachute jump: you have to get it right the first time.

Whatever the dangers of the action we take, the dangers of inaction are far, far greater.