I’ve often heard the expression Greater Good and have always come across the very same question about it: why the comparative form instead of the superlative form?
It is greater because it refers to a choice between two things.
I want to spend all my money on myself, for my good. But someone asks me to give up some of that money for another good purpose (charity, common public interests in the form of taxes, etc.). The suggestion is that it would be better if some of my money were spent on this other activity.
The choice is either
- all for me.
- Some for me and some for others
The latter choice is characterized by the requester as the greater good.
The phrase implies it is a better choice (greater) because it serves either more people or a higher purpose. It is comparative rather than superlative because the choice is among two things, not more.
But note that the phrase greatest good is also used.
Let's put this to use where it will do the greatest good. Let's research our options and give to the most efficient and effective of the 10 charities seeking funds.
The greater good is compared to the "great good" that every individual goal represents.
If I do not want to pay my taxes because it would mean I have more money, then I can very well argue that having more money is my "great good".
If I do pay my taxes, for the greater good, then that "good" is higher (morally) but also bigger (in size) than just the good of my own little person.
I think whenever the expression is used, there is always an implication that the "good" that is referred to is "greater" than some individual, not so "great" good. And "great" can indeed mean either morally superior or extending to a larger area (more people for instance).