What is the meaning of A courtyard common to all will be swept by none?

Answer 1

First, it's a truism. You read it and say, "yup, that's true." Just reflect on what you know about human nature and you'll have your answer. Shared responsibility does not work. If you have three kids and say "one of you needs to get the dishes washed while I'm gone", do you expect it will get done? Maybe the first time but most likely not the second. Or if you send a work email that requires a response to ten different people at the same time. Which of them will respond? None! Each one thinks that one of the other nine will take care of it. So if 30 people share the courtyard and each person is assigned a day on a schedule, it will get swept. But if the duty is simply left to the group as a whole, it will not.

Answer 2

Some tasks are more onerous than others, and if everyone is equal, who will volunteer to do the onerous tasks,; sweep the courtyard, clean the toilet, pick up garbage, etc, they are no more resonsible for the cleanliness of the courtyard than anyone else, why should they have to sweep it? The quote could also be interpreted as a statement about the inevitability of inequality. The comments and critiques on the economics idea of the "division of labor" might also be illuminating as to this quotes possible meaning.