Q. What does it mean “where there are no people, be a man”?

A. Of course, there are people around in that quote from Hillel in Ethics of Our Fathers (2:5 or 2:6, depending on your edition). It means if people are not living up to what they should be doing – even if you do not feel worthy or qualified – you be the man, you step up to the plate, where no one else (or not enough people) is doing what needs to be done.