“… normally we start from whatever behavior we want to get, then try to design a system that will produce it. Yet to do this reliable, we have to restrict ourselves to systems whose behavior we can readily understand and predict–for unless we can foresee how a system will behave, we cannot be sure that the system will do what we want.
“But unlike engineering, nature operates under no such constraint. So there is nothing to stop systmes like those at the end of the previous section from showing up. And in fact one of the important conclusions of this book is that such systems are actually very common in nature.
“But because the only situations in which we are routinely aware both of the underlying rules and overall behavior are ones in which we are building things or doing engineering, we never normally get any intuition about systems like the ones at the end of the previous section.”