Sound and Good

"It is our duty to concentrate  all our influence to make popular that which is sound and good, and unpopular that which is unsound".

What this means that if you do your homework you are doing sound and it is popular it is also good. When your not doing your homework it is unsound and it is not popular so you are not doing good. Another example is helping someone you are doing sound and it is popular because you are helping them so its good.