The poem
Oh, how I love Humanity, With love so pure and pringlish, And how I hate the horrid French, Who never will be English!
The International Idea, The largest and the clearest, Is welding all the nations now, Except the one that's nearest.
This compromise has long been known, This scheme of partial pardons, In ethical societies And small suburban gardens—
The villas and the chapels where I learned with little labour The way to love my fellow-man And hate my next-door neighbour.
C.S. Lewis comments on the idea in this poem, in Mere Christianity. He says if we love our fellow man, or rather our rather abstract idea of our fellow man, and hate our neighbor, then our love for our fellow man is largely imaginary, and our hate is completely real. If we are kind in our imagination, and rotten in our actions, we are in fact just rotten.
When a discussion of love arises I am reminded of St Thomas Aqinias' definition,"Willing the Good of the Other". This indicates something other than a carnal, emotional impulse, which on its own will not last. Love and sacrifice are intimately entwined.