The facts of nature are what they are, but we can only view them through the spectacles of our mind. Our mind works largely by metaphor and compariso… - Stephen Jay Gould

Bowing to the reality of harried lives, Rudwick recognizes that not everyone will read every word of the meaty second section; he even explicitly gives us permission to skip if we get “bogged down in the narrative.” Readers absolutely must not do such a thing; it should be illegal. The publisher should lock up the last 60 pages, and deny access to anyone who doesn't pass a multiple-choice exam inserted into the book between parts two and three.

The facts of nature are what they are, but we can only view them through the spectacles of our mind. Our mind works largely by metaphor and comparison, not always (or often) by relentless logic. When we are caught in conceptual traps, the best exit is often a change in metaphor — not because the new guideline will be truer to nature (for neither the old nor the new metaphor lies “out there” in the woods), but because we need a shift to more fruitful perspectives, and metaphor is often the best agent of conceptual transition.

I do not see why we should reject all genetic engineering because its technology might, one day, permit such a perversion of decency in the hands of some latter-day Hitler—you may as well outlaw printing because the same machine that composes Shakespeare can also set Mein Kampf. The domino theory does not apply to all human achievements. If we could, by transplanting a bacterial gene, confer disease or cold resistance upon an important crop plant, should we not do so in a world were people suffer so terribly from malnutrition? Must such a benefit imply that, tomorrow, corn and wheat, sea horses and orchids will be thrown into a gigantic vat, torn apart into genetic units, and reassembled into rows of identical human servants? Eternal vigilance, to recombine some phrases, is the price of technological achievement.