We think we know what we are doing. We have always thought so. We never seem to acknowledge that we have been wrong in the past, and so might be wrong in the future. Instead, each generation writes off earlier errors as the result of bad thinking by less able minds - and then confidently embarks on fresh errors of its own.

We are one of only three species on our planet that can claim to be self-aware, yet self-delusion may be a more significant characteristic of our kind.

We think we know what we are doing. We have always thought so.

Sometimes I think man needs to feel a special position within nature, and this leads him to believe that he is either specially hated by other animals or specially cherished. Instead of the truth, which is that he's just another animal on the plain. A smart one, but just another animal.

Nobody smart knows what they want to do until they get into their twenties or thirties.

To give up responsibility for our lives is not healthy.

Grant knew that people could not imagine geological time. Human life was lived on another scale of time entirely. An apple turned brown in a few minutes. Silverware turned black in a few days. A compost heap decayed in a season. A child grew up in a decade. None of these everyday human experiences prepared people to be able to imagine the meaning of eighty million years - the length of time that had passed since this little animal had died.