If chimpanzees have consciousness, if they are capable of abstractions, do they not have what until now has been described as 'human rights'? How smart does a chimp have to be before killing him constitutes murder?

I don't want to believe. I want to know.

The truth may be puzzling. It may take some work to grapple with. It may be counterintuitive. It may contradict deeply held prejudices. It may not be consonant with what we desperately want to be true. But our preferences do not determine what's true.

Recent research shows that many children without enough to eat wind up with diminished capacity to understand and learn (“cognitive impairment” ). Children don't have to be starving for this to happen. Even mild undernourishment — the kind most common among poor people in America — can do it.

If we can't think for ourselves, if we're unwilling to question authority, then we're just putty in the hands of those in power.

Atoms are mainly empty space. Matter is composed chiefly of nothing.

There are naive questions, tedious questions, ill-phrased questions, questions put after inadequate self-criticism. But every question is a cry to understand the world. There is no such thing as a dumb question.