Lyric discussion by azmuzik 

Cover art for A Song for a Son lyrics by Smashing Pumpkins, The

The songs seems to be about regretting not having a son and what that son could have been and the instruction for mothers to love theirs and to protect them. The narrator says that he is one of many more to come. It seems that there is something that caused him not to be a father and that it has happened to many more and that he won't be the last. It seems to be the degradation of society in a way. Idk, that's just what I take from it.

My Interpretation