After we are gone

Said of a US civil rights leader who died sometime around the start of 2010 and whose name I never discovered – 'He left more than he found'. This phrase I find quite pregnant with possible implications. We all leave the world changed in some way. By merely being here, we alter what goes on around us. However, this man left 'more'. This suggests that he contributed in some positive way; he didn't merely get involved for selfish reasons – that would have been a negative contribution in that it takes more than it gives.
Since reading and commenting on what was said of that man, I've heard a similar version – 'He left things better than he found them'. Interestingly, if one thinks about it, only human beings can leave things worse!