Change

"In an age when everything else is constantly changing, including our concept of human nature and of ultimate reality, what's the sense in clinging to the old? (Here I refer simply to old literary devices. Basic principles are different. They are eternal. What we need is ever new ways of expressing them.)"
-Poul Anderson, "Concerning Future Histories" IN SFWA Bulletin, Fall 1979, pp. 7-14 AT p. 14)

I agree that everything is changing and also that some principles are eternal even though, prima facie, that is a contradiction and requires further elucidation. Basic concepts do not change with the daily news but they have certainly changed. The phrase, "human nature," is used in two senses:

(i) the nature of humanity (obviously);
(ii) a particular idea about the nature of humanity, i.e., that human beings are fundamentally and unchangeably selfish.

My replies to (ii) are:

nothing is unchanging;
"human nature" has already undergone the greatest possible change, from non-existence to existence;
human beings have differentiated themselves as a species precisely by cooperatively changing their environment with hands and brain and changing themselves in the process.

Thus, our nature is cooperative change, not unchangeable selfishness. It is a historically recent discovery that we have evolved and are related to all other Terrestrial life which, in turn, is physically connected in more than one way with the rest of the cosmos. Many mental processes are unconscious and many motivations are concealed. These are major changes in our concept of human nature but let us consider ultimate reality tomorrow.