How we cite our quotes: (Chapter.Paragraph)
Quote #4
Though few realized it as yet, the fall of religion had been paralleled by a decline in science. There were plenty of technologists, but few original workers extending the frontiers of human knowledge. Curiosity remained, and the leisure to indulge in it, but the heart had been taken out of fundamental scientific research. (6.33)
This quote goes back to what we discussed in the first quote. You'd think the fall of religion would mean a rise in scientific philosophy, yet it doesn't work like that in the novel. Both human endeavors will suffer without support for curiosity about the unknown.
Quote #5
There was no point in developing rockets when the Overlords had infinitely superior means of propulsion, based on principles of which they had never given any hint. (8.11)
Think of it this way: Why bother studying for a test when the teacher will give you all the answers anyway? You'll pass the class, but will you really learn anything? When it comes to science, the Overlords gave humanity all the answers to the test, but mankind hasn't truly learned anything as a result.
Quote #6
[The ocean] was so alien, so remote from anything he had ever known that it set Jan's scalp crawling. And yet this was part of his own world… (11.32)
Jan's scalp tingling is that curious urge that sends him into the unknown to explore. Again, here we see that thread that connects the characters to the theme of science more so than all that awesome, futuristic technology (though awesome it is).