We can ignore even pleasure. But pain insists upon being attended to. God whispers to us in our pleasures, speaks in our conscience, but shouts in our pains: it is His megaphone to rouse a deaf world....No doubt pain as God's megaphone is a terrible instrument; it may lead to final and unrepented rebellion. But it gives the only opportunity the bad man can have for amendment. it removes the veil; it plants the flag of truth within the fortress of the rebel soul.
C. S. Lewis...we sacrifice other species to our own not because our own has any objective metaphysical privilege over others, but simply because it is ours. It may be very natural to have this loyalty to our own species, but let us hear no more from the naturalists about the "sentimentality" of anti-vivisectionists. If loyalty to our own species - preference for man simply because we are men - is not sentiment, then what is?
C. S. Lewis