But, later, coming back and reading what I have produced, I am unable to detect the difference between what came easily and when I had to sit down and say, "Well, now it's writing time and now I'll write.

Kindness is the beginning of cruelty.

It is so shocking to find out how many people do not believe that they can learn, and how many more believe learning to be difficult.

Then, as his planet killed him, it occurred to Kynes that his father and all the other scientists were wrong, that the most persistent principles of the universe were accident and error.

Law of the Minimum: "The worst potential competition for any organism can come from its own kind. The species consumes necessities. Growth is limited by that necessity which is present in the least amount. The least favourable condition controls the rate of growth."

If all those around you believe some particular thing, you will soon be tempted to share in that belief.

You aren't thinking or really existing unless you're willing to risk even your own sanity in the judgement of your existence.