Good vs Evil

Thus saith Aragorn:

Good and ill have not changed since yesteryear; nor are they one thing among Elves and Dwarves, and another among Men. It is a man's part to discern them, as much in the Golden Wood as in his own house.

In these days of moral relativism, a lot of emphasis is placed on time; that particular ideas are tied to specific times and places, and that there are no absolutes that carry across time.
I think Tolkien makes a nice concise point here. Both good and ill are described by Aragorn as unchanging, and not necessarily relative to different races.

Ever notice that past "evils" can be considered good over time, while most "good" things from the past are still considered good, or perhaps even looked back on with nostalgia?

Just something I thought about while making my way through the epic novel for the third (or is it fourth?) time.