"The routines in your code should be treated like tiny, highly polished diamonds, each one more exquisitely polished and finely cut than the next."
This makes no sense. Each routine can't be more exquisitely polished than the others. And if you try to make it make sense by interpreting 'next' strictly, to mean 'next in sequence', then it means your functions should get worse as development proceeds. Even if you replace 'next' with 'last', to try to turn it into a semi-coherent statement ("Each routine you write should be the best routine you've ever written") it's still bad advice: You should spend your time on the important questions, and not every function is equally important.
"The routines in your code should be treated like tiny, highly polished diamonds, each one more exquisitely polished and finely cut than the next."
This makes no sense. Each routine can't be more exquisitely polished than the others. And if you try to make it make sense by interpreting 'next' strictly, to mean 'next in sequence', then it means your functions should get worse as development proceeds. Even if you replace 'next' with 'last', to try to turn it into a semi-coherent statement ("Each routine you write should be the best routine you've ever written") it's still bad advice: You should spend your time on the important questions, and not every function is equally important.