Write a comparison and contrasting bubble for yourself. What do you think is good, if anything. Do you just hate all of it? Is the entire idea of conditioning a "perfect human" disgusting to you? Understand how you feel about the idea first. What did you think while you were reading this? Did you see only benefits? Did you think this could go well for some areas of human action? Write about that.
Now, write about what could go wrong with it.
In the steps above this is on scratch paper so that you can get your ideas together. Now, writing the paragraph essay - start with your main idea (it's awful, it's good, or, here are benefits and detriments). Go through your notes. Each note is a sentence for you to explore. You will wrap up the paragraph with your own opinion as the final sentence, (For example, even though the government in BNW saw more benefits than detriments to the conditioning and perfecting of humans through this manner, I cannot say I would ever agree because (pick your favorite argument).