Good was an abstract concept that incorporated a set of
religious, or moral ethics antithetical to Evil. Good was
usually constructive, beneficial, and orderly. Good could be
used to describe actions or individuals (even non-corporeal
entities), as well as ideas. The Excalbians were interested in
learning about the difference between Good and Evil when they
pitted Kirk, Spock, Surak and Abraham Lincoln against Genghis
Khan, Colonel Phillip Green, Kahless and Zora. (TOS: "The Savage
Curtain")