simple and effective

My editor at Intelligent Life writes:

I'm not convinced by the idea that instantly digestible = superficial. Great speakers from Jesus to Obama have come up with simple lines that run deep - 'Love your neighbour as yourself' for one. Rock music is full of them too. Give peace a chance... How many roads must a man walk down, before you call him a man? etc. The only thing wrong with the phrase 'simple but effective' is the but. The green movement, as you have written yourself, has not always found words to match the simple urgency of its message.