“Q: What's the difference between an enzyme and a hormone?A: You can't hear an enzyme.”

“Anyone who calls it "sexual intercourse" can't possibly be interested in actually doing it. You might as well announce you're ready for lunch by proclaiming, "I'd like to do some masticating and enzyme secreting.”

“....there is a difference between hearing and listening. You can't always help what you hear. But you can control what holds your interest, what you choose to dwell on.”

“Q: What's the difference between a tweaker and an elephant?A: The elephant will eat all your peanut butter.”

“Who could ever reckon up the damage done to love and friendship and all hopes of happiness by a surfeit or depletion of this or that neurotransmitter? And who will ever find a morality, an ethics down among the enzymes and amino acids when the general taste is for looking in the other direction?”

“Life cannot have had a random beginning ... The trouble is that there are about 2000 enzymes, and the chance of obtaining them all in a random trial is only one part in 10^40,000, an outrageously small probability that could not be faced even if the whole universe consisted of organic soup.”