“Perhaps walking is best imagined as an 'indicator species,' to use an ecologist's term. An indicator species signifies the health of an ecosystem, and its endangerment or diminishment can be an early warning sign of systemic trouble. Walking is an indicator species for various kinds of freedom and pleasures: free time, free and alluring space, and unhindered bodies.”

“The widespread abuse of prisoners is a virtually foolproof indication that politicians are trying to impose a system--whether political, religious or economic--that is rejected by large numbers of the people they are ruling. Just as ecologists define ecosystems by the presence of certain "indicator species" of plants and birds, torture is an indicator species of a regime that is engaged in a deeply anti-democratic project, even if that regime happens to have come to power through elections.”

“Desperate prayers may be an indication of spiritual health rather than a sign of spiritual deficiency.”

“It's in our genetics. It's why women are the master species. We give birth and we can walk in heels.”

“One species on the planet, and one species only, has reached the point of being able to have an impact on the evolutionary fortunes of all other species and upon the functioning of all ecosystems. We also have, in a way that is not true for any other species, a relationship to the planet as a whole and to the future. We live with all life.”

“You don’t speak again, unless to use your safe word or yellow to indicate you’re frightened.”“I was at yellow the minute I walked in the door.”