“I had learned that a dexterous, opposable thumb stood among the hallmarks of human success. We had maintained, even exaggerated, this important flexibility of our primate forebears, while most mammals had sacrificed it in specializing their digits. Carnivores run, stab, and scratch. My cat may manipulate me psychologically, but he'll never type or play the piano.”

“The most important scientific revolutions all include, as their only common feature, the dethronement of human arrogance from one pedestal after another of previous convictions about our centrality in the cosmos”

“When people learn no tools of judgment and merely follow their hopes, the seeds of political manipulation are sown.”

“We are here because one odd group of fishes had a peculiar fin anatomy that could transform into legs for terrestrial creatures; because the earth never froze entirely during an ice age; because a small and tenuous species, arising in Africa a quarter of a million years ago, has managed, so far, to survive by hook and by crook. We may yearn for a ‘higher answer’– but none exists”

“My potential salvation...must remain an unswerving commitment to treat generality only as it emerges from little things that arrest us and open our eyes with "aha" -- while direct, abstract, learned assaults upon generalities usually glaze them over.”

“I remember when we found the first population of living Cerion agassizi in central Eleuthera. Our hypothesis of Cerion's general pattern required that two predictions be affirmed (or else we were in trouble): this population must disappear by hybridization with mottled shells toward bank-interior coasts and with ribby snails toward the bank-edge. We hiked west toward the bank-interior and easily found hybrids right on the verge of the airport road. We then moved east toward the bank-edge along a disused road with vegetation rising to five feet in the center between the tire paths. We should have found our hybrids but we did not. The Cerion agassizi simply stopped about two hundred yards north of our first ribby Cerion. Then we realized that a pond lay just to our east and that ribby forms, with their coastal preferences, might not favor the western side of the pond. We forded the pond and found a classic hybrid zone between Cerion agassizi and ribby Cerions. (Ribby Cerion had just managed to round the south end of the pond, but had not moved sufficiently north along the west side to establish contact with C. agassizi populations.) I wanted to shout for joy. Then I thought, "But who can I tell; who cares?" And I answered myself, "I don't have to tell anyone. We have just seen and understood something that no one has ever seen and understood before. What more does a man need?”

“The most erroneous stories are those we think we know best - and therefore never scrutinize or question.”